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C O IV 



WEALTH OF 



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BOSTON METROPOLIT 



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COMMONWEALTH OF MASSACHUSETTS 



JOHN A. VOLPE, GOVERNOR 




IN COOPERATION WITH 

U.S. DEPARTMENT OF COMMERCE 
BUREAU OF PUBLIC ROADS 




INNER BELT AND EXPRESSWAY SYSTEM 

BOSTON METROPOLITAN AREA 

1962 

PREPARED FOR THE 

MASSACHUSETTS DEPARTMENT OF PUBLIC WORKS 

JACK P. RICCIARDI, COMMISSIONER 



I 



HAYDEN, HARDING & BUCHA 



A JOINT VENTURE REPORT BY 
M, INC. AND CHARLES A. 

C O N S ULTING ENGINEERS 
Boston, Massachusetts 



MAGUIRE & ASSOCIATES 







[Wet** Kk^H&.iti+a.^lr c 







Lithographed by Fine Impressions Inc. , Boston Massachusetts. 



•U40 Soldiers Field Road 
BOSTON 35. MASSACHUSETTS 

Telephone ALgonquin 4-6930 



no. 



CkM J- Wlf* & Jiiodatei 

Fourteen Court Square 
BOSTON 8. MASSACHUSETTS 

Telephone Richmond 20355 



CONSULTING ENGINEERS 



June 15, 1962 




Massachusetts u~v 
100 Nashua Street 
Boston, Massachusetts 



near Mr. Ricciardi: FPO RT on the " INNER 

V eS C ret.-^ U ation stud.es. ^ 

TQ7S We have also 
Tnd Expressway System. 



Respectfully, ^^ ^ Magu ire U Associates 

Harding & Buchanan, Inc. 
Hayden, Harding ^ JJ^d^B.; 



4i * 

Howard W. Holmes 



(f John L. Hayden 



JLH/HWH/hfm 



Joint 



Venturers 



„f Public Works Contract 
Massachusetts Depattmenr of y Connexions 

Boston Inner Belt ft" 








ACKNOWLEDGMENTS 



The advice and assistance provided by the ad- 
ministrative and technical staffs of the Massachusetts 
Department of Public Works and the Bureau of Public 
Roads of the United States Department of Commerce 
are gratefully acknowledged. ^^^ — 

For their cooperation in the compilation of de- 
tailed data, deep appreciation is expressed to the 
numerous officials and personnel of the 121 munici- 
palities within the Study Area and particularly to those 
in the 13 cities and towns in which either the Recom- 
mended or Alternate Location of the Inner Belt and 
Expressway System are located. Those 13 cities and 
towns are: 

Burlington Milton 

Cambridge Somerville 

Canton Winchester 

Lexington Woburn 
Medford 

Representatives of the many civic groups and 
associations, educational institutions and public utili- 
ties as well as federal and state agencies also were 
extremely helpful and merit sincere appreciation for 
their cooperation. 



Arlington 
Belmont 
Boston 
Brookline 





CONTENTS 



Glossary ....... 

Foreword ....... 

Summary of Conclusions and Recommendations 

PART I — INTRODUCTION 
Section 1 — General 

OBJECTIVE .... 

DESCRIPTION OF STUDY AREA . 
EXPRESSWAY SYSTEM 
OTHER FORMS OF TRANSPORTATION 
NEEDS AND DESIRES . 
Section 2 — The Study Procedure 



PART II — EXPRESSWAY LOCATION AND 
DESIGN CONSIDERATIONS 
Section 1 — Physical Location Considerations . 

METROPOLITAN. BOSTON EXPRESSWAY SYSTEM 

TERMINAL CONTROL POINTS 

TOPOGRAPHIC CONTROLS . 

LAND USE CONTROLS 

PUBLIC AND PRIVATE UTILITIES 
Section 2 — Design Considerations 

BASIC DESIGN CRITERIA 

OTHER DESIGN FEATURES . 

TRAFFIC CONSIDERATIONS . 
Section 3 — Economic and Aesthetic Considerations 

EFFECTS OF EXPRESSWAY LOCATION 

ROAD-USER BENEFITS . 

AESTHETIC CONSIDERATIONS 
Section 4 — Project Cost Considerations 

GENERAL 

CONSTRUCTION COSTS . 

RIGHT-OF-WAY COSTS 

OTHER COSTS .... 

PART III — TRAFFIC ANALYSIS 
Section 1 — Introduction 

PRIOR STUDIES 

REVIEW OF PREVIOUS REPORTS . 
INVENTORY OF AVAILABLE SURVEY DATA 



IV 

v 

vii 



-3 

-4 



11-1 
11-1 

11-4 

11-5 

11-6 

11-6 

11-7 

11-7 

11-7 

11-10 

11-11 

11-11 

11-11 

11-12 

11-13 

11-13 

11-13 

11-13 

11-14 



III- 1 

111-1 
111-2 
111-2 



ANALYSIS OF AVAILABLE SURVEY DATA 
RESULTS OF TRIAL ANALYSES . 
Section 2 — Mathematical Models for Traffic Analysis 

HISTORY AND BACKGROUND . 

The Need for Mathematical Models in Highway 
Planning ....... 

History of Potential, Gravity and Interaction Models 

Recent Mathematical Models for Highway Traffic 

Movement .... 

Recent Diversion Procedures 

THE MODEL .... 
Introduction .... 
The Need for a Single-Purpose Model 
Minimum Time Paths Through the Highway Network 
The Establishment of a Gravity Model . 
Loading the Network .... 

Section 3 — Application of the Present Model . 

REPRESENTATION OF THE PROBLEM 

Introduction ...... 

Representation of the Roadway Systems 

Selection of Representative Speeds 

Sociological Input Data .... 

Computer Programming .... 

Card-Input Preparation . 
MODEL EVALUATION 

Data Processing — Parameter Determination 

Statistical Analysis of Completed Model 

Screen-Line Analysis 

Traffic Generation and Distribution 

Traffic Assignment . 

Section 4 — Design Assignments 

INTRODUCTION .... 
FACTORS IN DETERMINATION OF ASSIGNED 

TRAFFIC VOLUMES 

General Location and Amount of Local Service 

Refinement of TISRO Ramp Assignments 

Average Daily Traffic 

Design Hour Volumes 
ASSIGNED TRAFFIC VOLUMES 

Inner Belt .... 

Southwest Expressway 



II 1-3 
111-3 
111-3 

111-5 

111-5 

111-5 

111-6 

111-8 

111-10 

111-10 

111-10 

111-10 

111-11 

111-13 

111-15 
111-15 
111-15 
111-15 
111-18 
111-19 
111-23 
111-25 
111-27 
111-27 
111-30 
111-33 
111-33 
111-36 

111-45 
111-45 

111-45 
111-45 
111-45 
111-45 
111-45 
111-48 
111-48 
111-52 



Route 3 and Northwest Expressways . 

Northern Expressway ..... 

PART IV — SOCIO-ECONOMIC ANALYSIS 

Section 1 — Introduction ..... 

PURPOSE OF STUDY 

METHOD OF ANALYSIS 

RELATIVE EFFECTS OF THE PHYSICAL AND 

FUNCTIONAL ANALYSES 

Section 2 — Population and Employment Projections . 

GENERAL 

METHODOLOGY FOR POPULATION AND 
EMPLOYMENT PROJECTIONS . 

ECONOMIC ASSUMPTIONS FOR EMPLOYMENT 
PROJECTIONS 

METHODOLOGY FOR DISTRIBUTION OF PROJECTED 
POPULATION AND EMPLOYMENT 
Section 3 — Actor Analysis of the Functional Effects . 

GENERAL .... 

LOCAL GOVERNMENT 

COMMUNITY INTEREST GROUPS 

COMMERCE AND BUSINESS . 

PUBLIC SERVICES 
Section 4 — Actor Analysis of the 

GENERAL .... 

LOCAL GOVERNMENT 

RESIDENTS DISPLACED 

COMMUNITY INTEREST GROUPS 

COMMERCE AND BUSINESS . 

PUBLIC SERVICES 
Section 5 — Actor Analysis by Community 

INTRODUCTION 

ARLINGTON 

BOSTON . 

BELMONT . 

BROOKLINE 

BURLINGTON 

CANTON . 

CAMBRIDGE 

LEXINGTON 

MEDFORD . 

MILTON . 



Physical Effects 



111-53 
111-54 



IV- 1 
IV- 1 
IV-2 

IV-2 
IV-3 
IV-3 

IV-3 

IV-5 

IV-6 
IV- 11 
IV- 11 
IV- 11 
IV- 11 
IV- 11 
IV- 12 
IV- 13 
IV- 13 
IV- 13 
IV- 13 
IV- 13 
IV- 13 
IV- 13 
IV- 14 
IV- 14 
IV- 14 
IV- 17 
IV- 18 
IV- 19 
IV-20 
IV-21 
IV-23 
IV-25 
IV-26 
IV-27 



POBLl 



NNER BELT AND EXPRESSWAY SYSTEM 




SOMERVILLE 

WINCHESTER 

WOBURN 

Section 6 — Summary and Conclusions 

PART V — EXPRESSWAY SYSTEM 
Section 1 — The Inner Belt Expressway . 

INTRODUCTION 

LOCATIONS OF THE CHARLES RIVER CROSSING . 
General ....... 

Subsurface Conditions , 

Massachusetts Turnpike Connections . 
Description of Recommended and Alternate 

Locations ....... 

Description and Analysis of Other Locations Studied 
LOCATIONS IN BOSTON AND BROOKLINE . 
General ....... 

Topography and Subsurface Conditions 
Description of Recommended and Alternate 

Locations ....... 

Description and Analysis of Other Locations Studied 
Analysis of Recommended and Alternate Locations 
LOCATIONS IN CAMBRIDGE, SOMERVILLE AND 

CHARLESTOWN 

General ....... 

Topography and Subsurface Conditions 
Description of Recommended and Alternate 

Locations ....... 

Description and Analysis of Other Locations Studied 
Analysis of Recommended and Alternate Locations 

SUMMARY 

Section 2 — The Southwest Expressway . 

GENERAL 

LOCATIONS STUDIED 

Description of Recommended and Alternate 

Locations ....... 

Description and Analysis of Other Locations Studied 
ANALYSIS OF RECOMMENDED AND ALTERNATE 

LOCATIONS 

Traffic Service ...... 

Physical and Functional Effects .... 

Cost Analysis ..... 



IV-29 
IV-30 
IV-31 
IV-32 

V-1 
V-l 
V-1 
V-l 
V-2 
V-2 

V-2 
V-2 

V-4 

V-4 
V-4 

V-5 
V-6 
V-6 

V-10 
V-10 
V-10 

V-1 1 
V-l 1 

V-12 
V-l 4 
V-l 6 
V-16 
V-l 6 

V-l 7 

V-17 

V-20 
V-20 
V-20 
V-22 



Road-User Benefit Analysis 
SUMMARY .... 

Section 3 — The Route 3 Expressway 

GENERAL 

LOCATIONS STUDIED 

Description of Recommended and Alternate 

Locations ....... 

Description and Analysis of Other Locations Studied 
ANALYSIS OF RECOMMENDED AND ALTERNATE 
LOCATIONS .... 

Traffic Service . . . . 

Physical and Functional Effects . 
Cost Analysis .... 

Road-User Benefit Analysis 
SUMMARY .... 

Section 4 — The Northwest Expressway 

GENERAL 

LOCATIONS STUDIED . . . 

Description of Recommended and Alternate 

Locations ....... 

Description and Analysis of Other Locations Studied 
ANALYSIS OF RECOMMENDED AND ALTERNATE 
LOCATIONS .... 

Traffic Service 

Physical and Functional Effects . 

Cost Analysis .... 

Road-User Benefit Analysis 
SUMMARY .... 

Section 5 — The Northern Expressway 

GENERAL 

LOCATIONS STUDIED 

Description of Recommended and Alternate 

Locations ....... 

Description and Analysis of Other Locations Studied 
ANALYSIS OF RECOAAMENDED AND ALTERNATE 
LOCATIONS . 
Traffic Service 

Physical and Functional Effects 
Cost Analysis . 
Road-User Benefit Analysis 
SUMMARY 
Appendix .... 



V-23 
V-23 
V-24 
V-24 
V-24 

V-24 
V-24 

V-28 
V-28 
V-29 
V-30 
V-30 
V-31 
V-32 
V-32 
V-32 

V-32 
V-33 

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V-36 
V-36 

V-36 
V-36 

V-38 
V-38 
V-38 
V-39 
V-39 
V-40 
V-l 03 



EXHIBITS 



Exhibit 

G-l 

L-l 

L-2 

L-3 
L-4 
1-5 
T-l 
T-2 
T-3 
T-4 
T-5 
T-6 

T-7 
T-8 
T-9 
T-10 
T-l 1 
T-l 2 
T-l 3 
T-14 
T-l 5 
T-16 
T-l 7 

T-l 8 

T-l 9 

T-2Q 

T-21 

T-22 

T-23 

T-24 

T-25 

T-26 

T-27 

T-28 

T-29 



Title 



The Boston Metropolitan Area . 

Expressway Construction Sequence 

Metropolitan Expressway System 

National System of Interstate and Defense High 
ways .... 

Interstate System of New England 

Typical Cross-Sections . 

Typical Cross-Sections 

The Traffic Study Area . 

Time Ratio Traffic Diversion Curves for Freeways 

Function for Travel Time . 

City and Town Location Map . 

Zone and Station Location Map 

Expressway Nets Coded For Electron 
Computation 

Function For Terminal Time 

Population Trend . 

Population Trend — Percent . 

Vehicle Registration and Travel 

Persons-Per-Vehicle Ratios 

Block Diagram of Programs 

Preparation of Computer Card-Deck Input 

Trip Transfer Comparison 

Link Load Comparison . 

Trip Transfers By Trip Travel Time 

Percentage of Total Trip Transfers By Trip Travel 

Time .... 

Trip Transfers By Trip Length . 

Percentage of Total Trip Transfers By Trip Length 

1945 Survey vs. Model Trip Ends 

Screen-Line Location Map 

Base Year and Design Year Trip Ends 

Survey Year and Design Year Isochrones 

District and Interchange Key Map 

1975 Free Assignment Volumes 

Cordon-Corridor Location Map 

Average Daily Traffic Design Capacity 

Traffic Factors and Applied Capacity Restrictions 

Trip Transfers By Time-Savings, 1975 



II 



NNER BELT AND EXPRESSWAY SYSTEM 



Inner Belt at 



Inner Belt At 



Inner Belt At 



Exhibit Ti,,e 

T-30 Trip Transfers By Time-Savings, 1959 

T-31 Base Year and Design Year TISRO Assignments . 

T-32 One-Way k From Empirical Data On Existing 

Expressways ...... 

T-33 Design Hour Volume Functions, Expressway Ramps 

T-34 Design Assignments: Inner Belt 

T-35 Interchange Design Assignments: 

Southwest Expressway 

T-36 Interchange Design Assignments: 

Northwest Expressway 

T-37 Interchange Design Assignments: 

Northern Expressway . 

T-38 Design Assignments: Southwest Expressway 

T-39 Design Assignments: Route 3, Northwest and 

Northern Expressways 

S-l The Socio-Economic Study Area 

S-2 Vacant Buildable Land Zoned Residential 

S-3 Vacant Buildable Land Zoned Commercial 

S-4 Vacant Buildable Land Zoned Industrial 

S-5 Population Densities 

S-6 Rings and Sectors of the Study Area 

S-7 Population Data 

S-8 ' Employment Data . 

S-9 Arlington Land Use, 1959 

S-10 Boston Land Use, 1959 . 

S-l 1 Belmont Land Use, 1959 

S-l 2 Brookline Land Use, 1959 

S-l 3 Burlington Land Use, 1959 

S-l 4 Canton Land Use, 1959 . 

S-l 5 Cambridge Land Use, 1959 

S-l 6 Lexington Land Use, 1959 

S-17 Medford Land Use, 1959 

S-l 8 Milton Land Use, 1959 . 

S-l 9 Somerville Land Use, 1959 

S-20 Winchester Land Use, 1959 

S-21 Woburn Land Use, 1959 

B-l Inner Belt Study Lines 

B-2 Southwest Expressway Study Lines — Sheet 1 

B-3 Southwest Expressway Study Lines — Sheet 2 



Page 

111-42 
111-44 

111-46 
111-48 
111-50 

111-51 

111-51 

111-51 
111-52 

111-53 

IV- 1 

IV-4 

IV-5 

IV-6 

IV-7 

IV-8 

IV-9 

IV- 10 

IV- 15 

IV- 16 

IV- 18 

1V-19 

IV-20 

IV-21 

IV-22 

IV-24 

IV-26 

IV-27 

IV-28 

IV-30 

IV-31 

V-3 

V-18 

V-19 



Exhibit Title 

B-4 Route 3 and Northwest Expressway 

Sheet 1 
B-5 Route 3 and Northwest Expressway 

Sheet 2 . . . . 

B-6 Northern Expressway Study Lines 

BASIC DESIGN EXHIBITS 
Recommended Location 

KEY MAP — RECOMMENDED 

LOCATION 
INNER BELT 

SOUTHWEST EXPRESSWAY 
INNER BELT AND MASSA- 
CHUSETTS TURNPIKE 
ROUTE 3 EXPRESSWAY 
NORTHWEST EXPRESSWAY 
NORTHERN EXPRESSWAY . 
INNER BELT ALTERNATE 
DESIGNS 
Alternate Location 

KEY MAP — ALTERNATE 

LOCATION . 
INNER BELT 

SOUTHWEST EXPRESSWAY 
INNER BELT AND MASSA- 
CHUSETTS TURNPIKE 
ROUTE 3 EXPRESSWAY 
NORTHWEST EXPRESSWAY 
NORTHERN EXPRESSWAY . 



Study Lines 
Study Lines 



B- 7 

B- 8 
B-l 2 

B-l 8 
B-20 
B-24 
B-27 



Exhibits 



thru B-ll 

thru B-l 7 

and B-l 9 

thru B-23 

thru B-26 

thru B-29 



B-30 thru B-39 



TABLES 

Table 

L-l 
L-fl 
L- III 



Page 

V-26 

V-27 
V-37 

Pages 

V-41 

V-42ff 

V-46fT 

V-52f 
V-54ff 
V-59fT 
V-63ff 

V-66ff 



L-IV 

T-l 

T-ll 

T-lll 



Titl( 

Design Criteria 

Vehicle Costs Per Mile At Average Speeds 

Ratios of Fair Market Value to Assessment — City 

of Boston . . . . .11-14 

Ratios of Fair Market Value to Assessment — 

Cities and Towns Other Than Boston . . 11-14 

Fitting - Parameter Set Values .... 111-27 
Screen - Line Analysis ..... 111-28 
Consolidated 1 975 Projected Trip Transfers . 111-34 



Table 

T-IV 
T-V 
T-VI 
T-VII 

T-VIII 
B-l 
B-ll 
B-l If 

B-IV 

B-V 

B-VI 
B-VII 

B-VIII 









B-IX 








B-X 


B-40 




V-77 


B-XI 


B-41 thru 


B-44 


V-78fF 




B-45 thru 


B-50 


V-82fF 


B-XII 
B-XIII 


B-51 and 


B-52 


V-88f 




B-53 thru 


B-57 


V-90ff 


B-XIV 


B-58 thru 


B-60 


V-95fF 




B-61 thru 


B-63 


V-99ff 

Page 


B-XV 
B-XVI 


• • 


• 


. 11-7 




rage Speei 


ds. 


11-12 





Title 

Statistical Data ..... 
Cordon - Corridor Analysis 
Assignments to 1975 Highway Network 
Correlating Factors Derived For Ramp - Use 

Function ...... 

Inner Belt Traffic Assignments . 

Inner Belt — Summary of Physical Effects . 

Inner Belt — Project Costs 

Inner Belt — Boston - Brookline — Road-User 

Benefit Analysis .... 

Inner Belt — Cambridge - Somerville - Charles- 
town — Road-User Benefit Analysis 
Southwest Expressway — Summary of Physica 

Effects 

Southwest Expressway — Project Costs 
Southwest Expressway — Road-User Benefit 

Analysis ...... 

Route 3 Expressway — Summary of Physica 

Effects 

Route 3 Expressway — Project Costs . 

Route 3 Expressway — Road-User Benefit Analysis 

Northwest Expressway — Summary of Physical 

Effects 

Northwest Expressway — Project Costs 
Northwest Expressway — Road-User Benefit 

Analysis ....... 

Northern Expressway — Summary of Physical 

Effects 

Northern Expressway — Project Costs 
Northern Expressway — Road-User Benefit 

Analysis ....... 



Page ( P U B L I 

1-36 
1-39 

1-43 



111-47 
111-49 
V-6 
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V-10 

V-14 

V-21 
V-22 

V-23 

V-28 
V-29 
V-30 

V-33 
V-34 

V-35 

V-38 
V-39 

V-40 



INNER BELT AND EXPRESSWAY SYSTEM 



III 



GLOSSARY 



AASHO: 

The American Association of State Highway Officials. 
ADT: 

Average Daily Traffic, the average two-way twenty-four-hour traffic volume for 

the stated year. 
ALL-OR-NONE: 

A reference to the traffic assignment procedure by which all trips of a given trip 

transfer are assigned to the shortest path and none to any alternate path. 
ASSIGNMENT MODEL: 

A mathematical model of the traffic assignment process, stated in mathematical 

terms primarily for computer application. 
BASE YEAR: 

The year of record upon which predictions of future traffic are based; in this 

Study the base year is 1959. 
BOSTON METROPOLITAN AREA: 

A general term referring to the area which includes the City of Boston and the 

complex of surrounding urban and suburban communities. 
BUREAU or BPR: 

The Bureau of Public Roads of the United States Department of Commerce. 
CAPACITY: 

The maximum number of passenger cars that can pass a given point on a lane or 

roadway during a stipulated time period under stipulated roadway and traffic 

conditions. 
CAPACITY RESTRAINT: 

A capacity stipulated for the assignment procedure for each expressway section, 

as the maximum traffic volume which may be assigned to that section under 

acceptable operating conditions for design purposes. 
CENTRAL ARTERY: 

The expressway through downtown Boston from City Square in Charlestown to 

Massachusetts Avenue in Roxbury, connecting the Northeast and Southeast Ex- 
pressways; officially named the John F. Fitzgerald Expressway and designated as 

Interstate Route 95. 
CENTRAL BUSINESS DISTRICT or CBD: 

That part of the Boston Metropolitan Area in the City of Boston, bounded on the 

the north by the Charles River, on the east by Boston Harbor, on the south by Fort 

Point Channel and South Bay, and on the west by Massachusetts Avenue. 
CENTROID: 

The weighted center of social and economic activity of a zone or sector; a node 

which represents this center in the network. 
CORE AREA: 

That part of the Boston Metropolitan Area in which is found the greatest density 

of social and economic activity; it includes the Central Business District and parts 

of South Boston, East Boston, Charlestown, Brookline, Cambridge, Somerville, 

Everett, and Chelsea. 
CORDON LINE: 

A line which circumscribes the CBD and at which traffic counts are surveyed or 

computed for comparison of traffic entering and leaving the area enclosed by the 

cordon-line. 
DADT: 

Directional Average Daily Traffic, the average one-way volume of traffic which 

occurs on a facility in a 24-hour period. 
DDHV: 

Directional Design Hour Volume, the one-way volume of vehicles per hour for 

which a facility is designed. 
DEPARTMENT or DPW: 

Massachusetts Department of Public Works. 
DESIGN CAPACITY: 

The volume of traffic in vehicles per day which a facility is designed to carry 

under acceptable operating conditions. 
DESIGN YEAR: 

The future year for which traffic volumes are predicted to serve as a basis for 

design; in this Study the design year is 1 975. 
DHV: 

Design Hourly Volume, the two-way volume of traffic for which a facility is de- 
signed, in vehicles per hour; the thirtieth highest hourly volume of the year; in 

urban areas, the larger peak hourly volume of the day. 
DOWNTOWN BOSTON: 

The Central Business District. 
FAIR MARKET VALUE: 

The price of a property at which a well-informed buyer is willing to purchase, and 

well-informed owner is willing to sell. 



FORTRAN: 

The IBM language developed to ease communication between man and computer; 
an acronym for FORmula TRANslation. 

FREE ASSIGNMENT: 

The traffic assignment to a highway facility resulting from unqualified use of the 
all-or-none assignment procedure. 

GRAVITY MODEL: 

A mathematical model of interactions in which the distribution functions vary as 
an inverse power of a distance measurement. Two such gravity models were used 
for this Study: one for the distribution of trips in Traffic Analysis, Part III, and one 
for the distribution of population and employment in Socio-Economic Analysis, 
Part IV. 

INNER BELT: 

The 1948 Master Highway Plan proposed the concept of the Belt Route as the 
entire inner circumferential expressway for the core area of Metropolitan Boston. 
The downtown portion of the Belt Route was called the Central Artery and is so 
referred to herein. The balance of the Belt Route, from the Southeast Expressway 
westerly and northerly to the Northeast Expressway, is referred to as the Inner 
Belt. Under the National System of Interstate and Defense Highways the South- 
west Expressway, a section of the Inner Belt from the Southwest Expressway to the 
Central Artery, the Central Artery and the Northeast Expressway are designated 
as Interstate Route 95; the Inner Belt from the Southwest Expressway westerly and 
northerly through Boston, across the Charles River through Cambridge, Somerville 
and the Charlestown section of Boston to an interchange with the Northeast Ex- 
pressway, is designated as Interstate Route 695. 

INTERCHANGE: 

A grade-separated intersection with one or more roadways, or ramps, which will 
permit transfer of vehicles between the intersecting roadways; a set of express- 
way access and corresponding egress ramps for a local street(s) or the direct 
connectors providing an interchange between major expressways. 

INTERSTATE ROUTE 90: 

The Massachusetts Turnpike and Turnpike Extension to the Inner Belt. That part 
of the Extension between the Inner Belt and the Central Artery is not part of the 
Interstate System. 

INTERSTATE ROUTE 93: 

The Northern Expressway from the Inner Belt northerly to Route 1 28, thence 
through Massachusetts and Central New Hampshire to St. Johnsbury, Vt, 

INTERSTATE ROUTE 95: 

Serves the eastern seaboard of the U. S. from Miami, Florida, to Houlton, Maine. 
The Southwest Expressway, the Inner Belt from the Southwest Expressway to the 
Central Artery, the Central Artery, and the Northeast Expressway are designated 
as Interstate Route 95 in the Boston area. 

INTERSTATE ROUTE 695: 

The Inner Belt from the Southwest Expressway (1-95) westerly and northerly 
through Boston, Cambridge and Somerville to the Northeast Expressway (1-95). 

ISOCHRONE: 

A line drawn on a map through all points which have equal travel times from a 
common point of origin called the isochrone-center; a travel-time contour. 

LINK: 

A unidirectional straight line connecting two nodes in a network to represent a 
portion of a highway system; it may be used in one-to-one correspondence with a 
street in the system, or in many-to-one correspondence to represent a group of 
parallel streets. 

MATHEMATICAL MODEL: 

A model in which the functions or operations of the prototype are represented 
by a mathematical equation or series of equations. 

MATHEMATICAL MODEL SYSTEM: 

A series of mutually compatible and interdependent mathematical models. 

MATRIX: 

A table listing the trip transfers and their volumes between each station, zone or 
sector and each other station, zone or sector in an urban area. 

M.D.C.: 

The Metropolitan District Commission. 

MINIMUM TIME PATH: 

The route from one point to another through a network for which the travel time 
is smallest. 

M.T.A. (MTA): 

The Metropolitan Transit Authority. 

NETWORK: 

A skeletonized representation of an urban street and highway system, consist- 
ing of nodes connected by straight-line links. 



NODE: 

A point of intersection of links of a network; such nodes may be used to repre- 
sent a variety of situations in the real highway system. 

O. & D.: 

Origin and Destination, referring to a surveyed or computed matrix, or table, of 
the volume of traffic which travels from each zone to each other zone in an urban 
area. 

O. & D. SURVEY: 

A field survey to determine the volume of traffic originating in or destined for 
each zone in the survey area. 

PARAMETER: 

A quantity in a mathematical equation to which may be assigned arbitrary values; 
two types of parameters are referred to herein: 

a. Fitting parameters, for the purpose of correlating computed results with sur- 
veyed or measured data; subsequent to such correlation, the values found 
become constants. 

b. Socio-economic parameters, which vary from year to year in the traffic 
analysis. 

ROUTE: 

See Interstate Route or State Route. 
SCREEN-LINE: 

A line described across an urban area, isolating a portion of that area, for the 

purpose of measuring or comparing traffic volumes crossing this line. Traffic 

crossing this line is known as the screen-line volume. 
SECTOR: 

A subdivision of a zone, established to obtain more detailed information than 

obtainable from the zone. 
SOCIO-ECONOMIC STUDY AREA: 

The group of 121 cities and towns generally within the area bounded by Inter- 
state Route 495, as shown on Exhibit S-l . 
SPIDER NET: 

A complete set of nodes and links representing the highway system of an urban 

area; a network. 
STANDARD METROPOLITAN AREA: 

The group of 65 cities and towns which comprise the Boston Standard Metropolitan 

Statistical Area as established by the 1 950 Census of the U. S. Department of 

Commerce, Bureau of Census; the traffic analysis was based on this area. 
STATE ROUTE 2: 

The Northwest Expressway from the Inner Belt in Cambridge and Somerville to 

Alewife Brook Parkway, thence along existing Route 2 to Route 1 28 and thence 

to the New York State line; a part of the Federal-Aid Primary Highway System. 
STATE ROUTE 3: 

From the New Hampshire line near Nashua to Route 128 in Burlington, thence to 

a connection with either the Northwest or the Northern Expressway; a part of the 

Federal-Aid Primary Highway System. 
TERMINAL TIME: 

Time spent at the start of a trip in getting a motor vehicle on the road, or at the 

end of a trip in locating and occupying a parking place. 
TISRO: 

Acronym of the Tlme-Saving-Rank-Order method of traffic assignment. 
TISRO ASSIGNMENT: 

A modified all-or-none method of assignment in which trip transfer volumes are 

assigned to a network in order of their potential time-savings via the expressway, 

from greatest to smallest. 
TRAFFIC STUDY AREA: 

The 65 cities and towns of the 1950 Boston Standard Metropolitan Statistical 

Area. 
TREE: 

The set of minimum-time paths from any given node to all other nodes in a net- 
work. 
TRIP TRANSFER: 

A traffic movement from a specific zone, sector or station of origin to a specific 

destination; a position in the O. & D. matrix. 
TRIP TRANSFER VOLUME: 

The average daily traffic volume of a trip transfer; an interzonal volume. 
ZONE: 

A sub-area of the Traffic Study Area, established to represent a logical grouping 

of traffic generators and attractors. A zone may be either a sub-division of a 

city or town, or one or more towns. 



IV 



NNER BELT AND EXPRESSWAY SYSTEM 




OREWORD 



The opening of the final section of the Central Artery (John 
F. Fitzgerald Expressway) on June 25, 1959, was an important 
milestone in a thirty-year effort to provide safe and efficient 
traffic service for this area and signalled the beginning of a new 
era for the Boston Metropolitan Area. The Mystic River Bridge, 
the East Boston Expressway, Route 128, the Southeast Express- 
way, the Northeast Expressway, the Callahan Tunnel, and Inter- 
state Route 93 represent many important miles of the Expressway 
System which have been either completed or started within the 
last fifteen years. The large traffic volumes attracted to the com- 
pleted parts of the system clearly demonstrate the immediate 
need for the early completion of the remaining expressways, and 
the necessity for continuous study of improvements to the trans- 
portation system, since traffic movements and highway location 
are influenced by constant changes in land use and population 
migrations. 

In accordance with the Agreement with the Commonwealth 
of Massachusetts, the purpose of this Study was the preparation 
of planning and location studies and the presentation of recom- 
mended basic design for certain remaining parts of the Express- 
way System. Specifically mentioned for study in this Agreement 
were the following: 

1 . The proposed Inner Belt Expressway, from the vicinity 
of the Prison Point Bridge in the Charlestown section of 
Boston, thence passing through Somerville, Cambridge, 



Brookline, and Boston and terminating at the southerly 
end of the present Central Artery in the Roxb 
tion of Boston. 

The proposed Southwest Expressway from Route 128 
in Canton, thence extending northerly through Boston 
to a connection with the proposed Inner Belt Express- 
way in the Roxbury section of Boston. 

3. The proposed Northwest Expressway from the vicinity 
of the intersection of Concord Turnpike and Alewife 
Brook Parkway in Cambridge, thence through Cam- 
bridge and Somerville to a connection with the pro- 
posed Inner Belt Expressway in Cambridge. 

4. The proposed Northern Expressway from the present 
terminus at Mystic Valley Parkway in Medford, thence 
through Medford and Somerville to a connection with 
the proposed Inner Belt Expressway in Somerville. 

5. The Route 3 Expressway from the present terminus at 
Route 128 in Burlington extending southerly to inte- 
grate with the proposed Expressway System. 

6. The junction of the proposed Massachusetts Turnpike 
Extension with the proposed Inner Belt Expressway 

In connection with this latter requirement, it was not until 
early 1962 that the exact status of the Turnpike was finally es- 
tablished. Meanwhile, it became necessary to forecast traffic in 
this Study to include traffic assignments for an expressway to 
the west, both as a free and as a toll facility, in order to provide 
data for either alternative. 

The scope and objectives of this Study of the Inner Belt and 
Expressway System involved the following: 

# Study of traffic desires in 65 communities of the Boston 
Metropolitan Area in determination of realistically projected 1975 
design volumes of traffic which may be expected on the Inner 
Belt and Expressway System, including interchange ramps. 

• Study of social and economic effects attributable to the 
proposed Inner Belt and Expressway System in 121 communities 
comprising the Economic Study Area including estimates of future 
population, employment, economic development and community 
benefits realized from the Expressway System. 




pub: 






• Study of pertinent engineering and economic data in 
preparation of basic designs, estimates of the cost of construction, 
estimates of the cost of acquisition of right-of-way, and road-user 
benefits. 




a 



>tudy of alternative locations for the Inner Belt and Ex- 
pressway System in consideration of the above data. 

• Development and presentation of the basic design of the 
Recommended and Alternate Locations for the Inner Belt and Ex- 
pressway System. 

The basic concept of the Expressway System is pubh 
accepted, and the projected desires and the engineering data 
gathered during the course of this Study cleqrly indicate the need 
for the Expressway System as well as other improvements in the 
transportation system. 

Continuous liaison was maintained with officials and inter- 
ested citizen groups of the cities and towns in the Study Area to 
obtain their constructive criticism and comments. Public hearings 
were held in Boston and Cambridge in the spring of 1960 to per- 
mit the general public to voice their opinions concerning location 
of the Inner Belt and the Northern Expressway. 

The selection of the Recommended and Alternate Locations 
for the various expressways was unusually complex due to the 
heterogeneous character of development of the Study Area. There- 
fore, in order to develop feasible locations for each expressway, 
it was necessary to establish detailed engineering data pertinent 
to each alternative, to analyze the advantageous and disadvan- 
tageous short and long-range effects, and to develop factual com- 
parisons essential to the selection of expressway locations. This 
was done with the utmost care. 




Since the inevitably changing conditions of a dynamic econ- 
omy have a continuing impact on the selection of expressway 
locations, January 1, 1962 was established as the limiting date 
for consideration of factors that might affect the recommendations 
contained herein. 



/ 




UMMARY OF CONCLUSIONS AND RECOMMENDATIONS 




The vigorous industrial, commercial, governmental, 
and residential development currently in progress in 
the Boston Metropolitan Area dramatizes the need 
to accelerate the completion of the Inner Belt and 
Expressway System. The traffic volume generated 
by this vigorous growth, witnessed by the congestion 
on the present network of roads and streets leading 
to and within the Boston Metropolitan Area, is force- 
ful evidence that the completion of the Expressway 
System must receive the highest priority in the highway program of 
the Commonwealth. 

Predicted increases of 270,000 in population, 70,000 in em- 
ployment and 280,000 in motor vehicle registration within sixty-five 
communities of the Boston Metropolitan Area by the year 1975, 
accentuated by the current vigorous rebirth of the Core Area and 
the concurrent rapid growth of suburban areas, are indisputable 
testimony that augmented and improved transportation facilities 
are vitally needed. The philosophy of an Inner Belt and Radial 
Expressway System was presented in the Master Highway Plan for 
the Boston Metropolitan Area in 1948, and was adopted by the 
Commonwealth as the basis for a long-range program of highway 
improvements. This Study reaffirms the validity of an Inner Belt 
and Radial Expressway concept and the urgency for early com- 
pletion of the Expressway System. 

The Central Artery, the Southeast Expressway, the Northeast 
Expressway, and a portion of the Northern Expressway were com- 
pleted as the initial phase of this long-range program. Develop- 
ments which have occurred, including the construction of these 
sections of the Master Highway Plan, have had a profound effect 
on the traffic pattern of the Metropolitan Area, far beyond that 
anticipated at the time of the 1948 Study. Significant changes in 
the locations of the Inner Belt and the Expressways recommended 
herein, as compared with earlier studies, have resulted from shifting 
and rapidly expanding population and employment, increased use 
of motor vehicles, striking changes in land-use patterns, decline pf 
mass transit patronage and railroad service, and construction of 
expressways, together with technological advances in highway plan- 
ning and a more comprehensive understanding of the complex prin- 
ciples of traffic movements. 



The Government Center Project in the Scollay Square Area, 
with city, state, and federal office buildings, the Prudential Center 
Project, the New York Streets Project, the West End Project, the 
Whitney Street Project, the North Harvard Project, the 350-acre in- 
dustrial development site in the lower Roxbury Area, the Washing- 
ton Park Renewal Area, the 71 -acre site at Donnelly Field, the 
Houghton Renewal Area, the 160-acre Cambridgeport Renewal 
Area, the Massachusetts Institute of Technology Research Center, 
and the 60-acre project in the Linwood-Joy Area, are prime illus- 
trations, within the Core Area, of changes in land-use patterns, 
population shifts, and employment potentials in expression of the 
theme of expansion of the mid-twentieth century. 

The suburban areas have also experienced industrial and 
residential development in the past ten years, beyond the imagina- 
tion of the most hopeful planners. This growth pattern, which has 
received world-wide recognition, was due primarily to the ambi- 
tious construction of Route 128, the first circumferential expressway 
for Metropolitan Boston. 

This dramatic revitalization of the core area, this imaginative 
development of the suburban areas, this collective mood of con- 
fident expansion characteristic of the Boston Metropolitan Area, 
is strong evidence of the desire of an enthusiastic populace to real- 
ize the full potential of their region. An intelligently planned and 
executed system of coordinated transportation media, responsive 
to the needs of both the present and the future will result in a 
vigorous regional economic growth. In order to develop such a 
system, it is imperative that the same bold steps be taken that 
have been taken in the renewal of the core and suburban areas and 
in the development of the Expressway System. 

In addition to new expressways, the necessity for an expanded, 
modernized and attractive public transit system integrated with 
all passenger transportation facilities is fully recognized. Such a 
system would provide an economical and rapid form of transporta- 
tion in the urban area, and would greatly reduce street and high- 
way congestion by serving large numbers of passengers in relation 
to the space required. Areas of concentrated economic activity 
would be integrated with the Core Area by the continuity of a 
coordinated mass transportation and expressway system, capable 
of serving the requirements of the Boston Metropolitan Area, 



A vital component of the integrated transportation system is 
an expressway system for the movement of large numbers of 
passenger and commercial vehicles within and through the core 
and suburban areas. The authorization and direction of this Study 
by responsible federal and state agencies resulted in a concentrated 
and coordinated effort to analyze all related factors, in order to 
provide the best solution for the expressway component of the trans- 
portation system. The complex of studies directed toward this need 
produced many alternative locations for the Inner Belt and Express- 
way System. A comparative evaluation of these alternatives re- 
sulted in the selection of those locations which will best serve the 
entire area. These locations have been designated as the Recom- 
mended and Alternate Locations, and the expressways, built in the 
Recommended Locations, will act as a continuing stimulus to the 
economy of the area, and will best serve as part of the Interstate 
and Defense Highway System. The Recommended Locations place 
the facilities where they best serve the major traffic desires with the 
highest possible degree of service. The Alternate Locations provide 
an adequate but less satisfactory solution, in weighted consideration 
of numerous complex factors upon which the selection of locations 
was made. 

Conclusive evidence exists that the completed Expressway Sys- 
tem will provide manifold benefits for the Boston Metropolitan Area. 
To realize the full potential of the Expressway System, vigorous 
coordinated action between Federal and State Governments and 
the communities of the Boston Metropolitan Area is necessary. The 
displacement of businesses and residences resulting from urban 
renewal projects and expressway projects should be planned in 
unison and in consideration of the absorptive capacity of existing 
and proposed facilities. Coordinated planning presents an oppor- 
tunity to work together to achieve the mutually beneficial goal of 
completing the vitally-needed Expressway System, and at the same 
time realizing the planning objectives of the individual communities. 

In sum, the achievement of the Inner Belt and Expressway 
System, carefully integrated with a comprehensive transportation 
plan and the many public and private developments now proceed- 
ing, will earn the Boston Metropolitan Area the right to valid antic- 
ipation of a continuing position of prominence among the urban 
regions of the United States. 



NNER BELT AND EXPRESSWAY SYSTEM 



VII 




SOUTHWEST EXPRESSWAY 

(Interstate Route 95) 

The Recommended Location of the Southwest Expressway ex- 
tends from Route 1 28 in Canton by way of the Neponset Valley 
Reservation to Readville, crosses to the west of and parallel to the 
New York, New Haven & Hartford Railroad to Jackson Square in 
Roxbury where it recrosses the railroad to an interchange with the 
Recommended Location of the Inner Belt at Madison Park in Boston. 

Estimated Construction Cost $ 48,296,000 

Estimated Right-of-Way Cost $ 16,092,000 

Total Cost $ 64,388,000 



NORTHERN EXPRESSWAY 

(Interstate Route 93) 

The Recommended Location of the Northern Expressway ex- 
tends from the end of the existing construction, at Mystic Valley 
Parkway in Medford, by way of Mystic Avenue to an interchange 
with the Recommended Location of the Inner Belt in the Boston & 
Maine Railroad yards in Somerville and Boston. 

Estimated Construction Cost $ 13,686,000 

Estimated Right-of-Way Cost $ 4,042,000 

Total Cost $ 17,728,000 



RECOMMENDED INNER BELT AND 
EXPRESSWAY LOCATIONS 

The comparative service, features and costs of the Recom- 
mended Location of the Inner Belt and Expressway System are pre- 
sented in detail in Part V; however, for convenience of reference, 
a short summary of applicable costs for the Recommended Locations 
is included here. 

INNER BELT EXPRESSWAY 

(1-695 and Section of 1-95) 

The Recommended Location of the Inner Belt Expressway ex- 
tends from the southerly end of the Central Artery, near Massachu- 
setts Avenue, by way of Ruggles Street and the Fenway in Boston, 
to a double-deck bridge across the Charles River, parallels Brookline 
and Elm Streets in Cambridge, enters the Boston & Maine Rail- 
road Yard in Somerville and Boston, and terminates in the vicinity 
of Prison Point Bridge at the end of a section of the Inner Belt for 
which the design has been completed. 

Estimated Construction Cost $144,793,000 

Estimated Right-of-Way Cost $ 24,025,000 

Total Cost $168,818,000 



ROUTE 3 EXPRESSWAY 

The Recommended Location of the Route 3 Expressway extends 
from Route 1 28 in Burlington by way of Great Meadow in Lexington, 
to existing Route 2 at Appleton Street, then follows existing Route 2 
to Alewife Brook Parkway in Cambridge, where it joins the North- 
west Expressway. 

Estimated Construction Cost $ 27,080,000 

Estimated Right-of-Way Cost $ 6,034,000 

Total Cost $ 33,114,000 



NORTHWEST EXPRESSWAY 

The Recommended Location of the Northwest Expressway ex- 
tends from the Recommended Route 3 Expressway at Alewife Brook 
Parkway in Cambridge by way of a line parallel to the Fitchburg 
Branch of the Boston & Maine Railroad, passing south of Porter 
Square, to an interchange with the Recommended Location of the 
Inner Belt in Cambridge. 

Estimated Construction Cost $ 34,567,000 

Estimated Right-of-Way Cost $ 5,886,000 

Total Cost $ 40,453,000 



ANNUAL ROAD-USER BENEFITS 

Benefits will accrue to the users of the Expressway System as a 
result of reduced operating costs, reduced travel time, increased 
comfort and convenience, and a reduction of the accident rate, 
as compared with travel over existing streets between comparable 
points. Such benefits are referred to as "Road-User Benefits" and 
have been calculated on the basis of annual savings accruing to the 
users of each expressway of the system. 



ANNUAL SAVINGS FOR THE ROAD-USER 
(For the Recommended Location of Each Expressway) 

Inner Belt $43,883,000 

Southwest Expressway 14,290,000 

Route 3 Expressway 11 ,630,000 

Northwest Expressway 12,403,000 

Northern Expressway 4,029,000 

Total Annual Savings . . $86,235,000 

These values show a total annual savings of $86 million per 
year for users of the Expressway System as compared with travel 
over existing streets. 



VIII 



NNER BELT AND EXPRESSWAY SYSTEM 



PUBLIC 




EXISTING EXPRESSWAYS 
OTHER PROPOSED EXPRESSWAYS 
CONSTRUCTION STAGE NO. I 
CONSTRUCTION STAGE NO.2 
CONSTRUCTION STAGE NO.3 
CONSTRUCTION STAGE N0.4 



CONSTRUCTION PROGRAM 

The recommended construction schedule for the Inner Belt and 
Expressway System, is shown in Exhibit G-l and is presented below 
together with project costs for the Recommended Locations. The 
schedule is based on the relative urgency of the traffic needs of the 
Boston Metropolitan Area with due regard for the construction of 
usable sections which provide the earliest relief from traffic con- 
gestion. Construction of the section of the Inner Belt from the inter- 
change of the Central Artery with the Northeast Expressway, to 
Prison Point Bridge in Charlestown should commence in 1963. Its 
estimated cost, $8,223,000 is not included in the project cost 
given below. 



STAGE NO. 1 — Construction to Start 1963-1965 



Northern Expressway 
(1-93) 

Inner Belt 
(1-695) 

Inner Belt 
(1-695) 

Northern Expressway 
(1-93) 



From the Mystic Valley Parkway (Route 16), 
Medford, to Foss Park, Somerville. 

From Prison Point Bridge to and including the 
Northern Expressway (1-93) interchange in Somerville. 

From Brookline Avenue to Soldiers Field Road, 
Boston, with connections to the extension of the 
Massachusetts Turnpike. 

From Foss Park, Somerville, to the interchange with 
the Inner Belt in Somerville. 

1: 



TOTAL COST OF STAGE NO. 

STAGE NO. 2 — Construction to Start 1964-1966 

Inner Belt From Massachusetts Avenue to Columbus Avenue, 

(1-95) & (1-695) Boston, and the Southwest Expressway to Jackson 

Square. 

From Route 128, Canton, to Forest Hills, Boston. 



Southwest Expressway 
(1-95) 

Route 3 Expressway 
(Route 3 and Route 2 
— Primary System) 



From Appleton Street, Arlington, to Alewife Brook 
Parkway, Cambridge. 



TOTAL COST OF STAGE NO. 2 
STAGE NO. 3 — Construction to Start 1966-1968 

Inner Belt 
(1-695) 

Southwest Expressway 
(1-95) 

Inner Belt 
(1-695) 

TOTAL COST OF STAGE NO. 3: 

STAGE NO. 4 — Construction to Start 1967-1969 

Inner Belt 
(1-695) 

Northwest Expressway 
(Route 2 — 

Primary System) 

Route 3 Expressway 
(Route 3 — 
Primary System) 



From the Northwest Expressway in Cambridge to the 
Northern Expressway in Somerville. 

From Forest Hills, Boston, to Jackson Square, Boston. 



From Soldiers Field Road, Boston, to and including 
the Northwest Expressway interchange. 



From Columbus Avenue, Boston, to Brookline Avenue, 
Boston. 

From Alewife Brook Parkway, Cambridge, to the 
interchange with the Inner Belt in Cambridge, 
including ramps to McGrath Highway. 

From Route 128, Burlington, to Route 2 at Appleton 
Street, Arlington. 



TOTAL COST OF STAGE NO. 4: 



TOTAL COST OF ALL STAGES: 



Project Cost 
$ 5,156,000 

$ 25,748,000 

$ 30,541,000 

$ 12,572,000 
$ 74,017,000 

$ 29,593,000 

$ 41,119,000 
$ 14,790,000 

$ 85,502,000 

$ 33,166,000 

$ 23,269,000 

$ 25,721,000 

$ 82,156,000 

$ 24,049,000 
$ 50,811,000 

$ 7,966,000 

$ 82,826,000 
$324,501,000 



Exhibit G-l 
EXPRESSWAY CONSTRUCTION SEQUENCE 



INNER BELT AND EXPRESSWAY SYSTEM 



IX 



SUMMARY OF RECOMMENDATIONS 



It is recommended that: 



The Inner Belt and Expressway System be constructed in 
the Recommended Locations, which best serve the ve- 
hicular traffic requirements of the Boston Metropolitan 
Area. 



he Commonwealth take the necessary steps to pro- 
vide an effective mass transportation system for the 
Boston Metropolitan Area that is coordinated and in- 
tegrated with the Inner Belt and Expressway System. 






A coordinated program of local street improvements 
be initiated in order to realize the full potential of the 
Expressway System. 



Additional study of the following major improvements be 
made so as to plan effectively to provide increased capacity 
for the Expressway System and the arterial streets: 



1 . Supplementation of the Central Artery by provid- 
ing an additional expressway facility or a con- 
tinuous surface arterial parallel to the Central 
Artery. 



2. Construction of a direct connection from the North 
east Expressway to Leverett Circle. 



3. Reconstruction of McGrath and O'Brien Highways 
to Leverett Circle. 













Particular attention be directed to the recommended 
construction schedule and every effort be expended to 
advance this schedule so as to provide relief from 
traffic congestion as early as practicable. 



The design and construction of the Massachusetts Turn- 
pike and Inner Belt connection be coordinated in order 
to achieve maximum benefit and economy of construc- 
tion. 




The Commonwealth continue its study of the ever- 
changing factors influencing and dictating highway re- 
quirements. 




The City of Boston continue its off-street parking pro- 
gram, and the cities of Cambridge and Somerville and 
the Town of Brookline initiate such programs integrated 
with the transportation system. 



The provision of additional lanes for the Southeast 
Expressway north from Columbia Circle. 



5. Construction of direct connections from the South- 
east Expressway into the South End Urban Renewal 
Area. 






6. Construction of an intermediate circumferential 
highway which would utilize portions of Revere 
Beach, Mystic Valley, Alewife Brook and Fresh 
Pond Parkways, the proposed Charles River Park- 
way, Market Street, Chestnut Hill Avenue, the 
Arborway, Morton Street, and Gallivan Boulevard. 



INNER BELT AND EXPRESSWAY SYSTEM 



PUBLIC 




PART I 



INTRODUCTION 



SECTION 1- GENERAL 



PUBLIC 



OBJECTIVE 

This Report presents the planning and location studies under- 
taken for the development of the Inner Belt and Expressway Sys- 
tem for the Boston Metropolitan Area, consisting of the Inner 
Belt (Interstate Route 695), with a connection to the Massachusetts 
Turnpike Extension, and the following radial expressways: the 
Southwest Expressway (Interstate Route 95); the Northern Express- 
way (Interstate Route 93); and Federal Primary Highways Route 3 
(southerly from Route 128) and the Northwest Expressway. The 
basic objective of these studies was to determine the best location 
for these expressways. Fundamental factors considered in location 
determinations were traffic desires, social and economic effects, 
neighborhood planning, topography, design criteria, military ad- 
vantages, and related matters affecting the 65 communities of the 
Traffic Study Area and 121 communities of the Socio-Economic 
Study Area of this Report. 



DESCRIPTION OF STUDY AREA 

Boston, the cultural center of New England, is the hub of 
this Economic Study Area which extends south to Taunton, west 
to Marlborough and north to North Andover. The Mystic River, 
Charles River, and Neponset River have their sources near the 
outer fringes of the area and converge from the north, west, and 
south on Boston Harbor, where extensive port facilities have de- 
veloped at the confluence of the harbor and the Mystic and Charles 
Rivers. The 1960 Federal Census for this area records a total 
population of approximately 3,200,000. As one of the country's 
major research, scientific, educational, medical, manufacturing, 
and shipping centers, opportunity for the employment of more 
than 1,200,000 is presently available. 

The existing major surface streets of the Boston Metropolitan 
Area have the appearance of a giant spider web. The pattern 
consists essentially of four rings crossed by streets radiating from 
the Boston Central Business District. The innermost ring surrounding 
the business district consists of Commercial Street, Atlantic Avenue, 
Kneeland and Stuart Streets, Charles Street, Nashua Street, and 



Causeway Street. The second ring is formed by Columbia Road 
starting at Pleasure Bay on the southwest shore of Boston Harbor, 
and thence along Massachusetts Avenue, Memorial Drive, and 
the Prison Point Bridge to Charlestown. This ring links South 
Boston, Back Bay, and the Charlestown areas. The third ring is 
made up of a combination of boulevards and major streets starting 
at Neponset Circle, south of Boston, and consists of Gallivan Boule- 
vard, Morton Street, the Arborway, Jamaicaway, Harvard Street, 
Boylston Street, Kirkland Street and Washington Street. The outer- 
most ring is formed by the Neponset Valley, Turtle Pond, West 
Roxbury, Hammond Pond, Fresh Pond, Alewife Brook, Mystic 
Valley and Revere Beach Parkways. Radiating from the central 
core and intersecting those rings, are Dorchester Avenue, Morrissey 
Boulevard, Blue Hill Avenue, Hyde Park Avenue, Washington Street, 
Veterans of Foreign Wars Parkway, Route 9, Huntington Avenue, 
Beacon Street, Commonwealth Avenue, Soldiers Field Road, Storrow 
Drive, Massachusetts Avenue, Broadway, Cambridge Street, Mc- 
Grath Highway, and Rutherford Avenue. 



EXPRESSWAY SYSTEM 

The problem of traffic congestion in the Boston Metropolitan 
Area has been the subject of many studies in previous years by 
various public agencies and civic groups. The first comprehensive 
report on the problem of traffic congestion was prepared in 1930 
by Robert Whitten. One of Mr. Whitten's proposals involved an 
elevated highway running from the North End of the City of Boston 
to the South End. The present Central Artery closely coincides 
with this route. 

The Central Artery, completed in 1959 as an initial project in 
the development of the expressway system outlined in the 1948 
Master Highway Plan, is unique in that it contains perhaps the 
widest vehicular tunnel in the world. An outstanding example for 
the entire country of excellent highway planning is the circum- 
ferential highway located about ten miles from the Boston Central 
Business District and designated as Route 128, which replaced an 
earlier route composed of local roads connecting and passing 
through the business centers of many of the cities and towns sur- 



rounding Boston. The completion of Route 128 provided, for the 
first time, an effective high-speed circumferential highway around 
the many congested districts of the Boston Metropolitan Area. 
The timing and location of this highway were ideal in making ac- 
cessible the land necessary to satisfy the vigorous movement of 
people and industry in the post-war period. 

Other completed parts of the expressway system serving the 
Boston Metropolitan Area consist of the Northeast Expressway 
to Route C-l in Revere, the East Boston Expressway including a 
connection to Logan International Airport, the Southeast Expressway 
to Hingham, the Fall River Expressway from Fall River to Route 
128, the Massachusetts Turnpike from the New York State line to 
Route 128, and the Northern Expressway to New Hampshire. The 
construction of the Massachusetts Turnpike Extension from Route 
1 28 to downtown Boston has commenced and is expected to be 
completed by 1965. 

A remarkable surge of extensive diversified industrial de- 
velopment is taking place within the area, particularly along Route 
128. Industrial parks and regional and local shopping centers 
in the cities and towns within the area are receiving great impetus 
as a result of the encouragement of local governments and the 
efforts of federal and state governments to improve the highway 
system. 



OTHER FORMS OF TRANSPORTATION 

Excellent sea, air and rail transportation facilities are avail- 
able to this area. Boston Harbor's deep-water channel leads di- 
rectly to the open sea and is at least 200 miles closer to Europe 
than any other major east-coast seaport. The Logan International 
Airport is less than three miles from the Boston Central Business 
District. Three railroads link the Port of Boston with the entire 
New England Area. The New York, New Haven & Hartford Rail- 
road serves the south, the Boston & Maine Railroad the north, and 
the New York Central Railroad the west. This railroad network 
began with the construction of a rail line from Quincy to Boston. 
Rail service to Providence, and connections to New York, to Maine, 
and to the west followed. These railroads set the pattern of radial 



NNER BELT AND EXPRESSWAY SYSTEM 




1-1 



transportation lines outward from the "hub" at Boston. 

Mass transit facilities began with the construction of an 
electric surface car line from Boston to Brookline, which started 
operating near the turn of the century. Through the years, these 
transit facilities were extended to the outlying points of Forest 
Hills, Everett, Harvard Square and Ashmont. Since World War 
II, extensions of rapid transit facilities have been made from Boston 
to Newton along the right-of-way of the Highland Branch of the 
Boston & Albany Railroad, and from Boston to Revere. However, 
much greater expansion is necessary to keep pace with the growth 
of the area. Extensions of mass transportation well into the sub- 
urban areas will attract many riders to the improved facilities, thus 
reducing vehicle travel desires. For instance, in the Greater Boston 
Economic Study Committee Report of 1960, it was asserted that 
the Highland Branch MTA service, as presently constituted, was 
furnishing the equivalent of one vehicular traffic lane during peak 
hours, that peak-period traffic congestion in Downtown Boston 
was reduced by about 7 per cent, and that 1300 parking spaces 
were freed for other use. In large metropolitan areas such as 
Boston, the solution of the transportation problem lies in developing 
a system of streets and expressways integrated with a mass trans- 
portation system including railroads, rapid transit, and buses. 



INTEGRATION WITH MASS TRANSIT 

The desirability of coordinating the design and location of 
the radial expressways with potential mass transit expansion was 
recognized in this Study, and expressway locations along existing 
railroad and mass transit rights-of-way were considered in detail. 
Where such a passenger facility occurred within a corridor of 
traffic desire, plans were developed to utilize either the right-of- 
way itself, or the area adjacent thereto for the location of the 
expressway. The location of the expressways and rapid transit 
or railroad facilities in the same corridor serves two functions. 
Primarily this arrangement will permit the road user to leave the 
expressway some distance from the core area, park in fringe park- 
ing lots located for the convenient transfer of commuters, and 
continue by rapid transit. Secondly, but equally important, this 



arrangement will utilize only one corridor for the transportation of 
goods and individuals and thereby permit more efficient use of 
adjoining land. 

Southeast of Boston, railroad passenger service does not 
presently exist, and the rapid transit system extends only as far as 
Ashmont Station in Dorchester. The Southeast Expressway serves 
vehicular traffic to the South Shore, and is a typical example of 
the need to supplement expressway service with mass transporta- 
tion service, in that this recently completed expressway facility is 
even now operating at capacity during peak hours. 

Southwest of Boston, railroad passenger service is available, 
but rapid transit ends at the Forest Hills Station. The Southwest 
Expressway will complement these mass transportation facilities, 
but improvements to and the extension of the rapid transit in this 
area are also needed. 

West of Boston, railroad passenger service is limited and 
the rapid transit Highland Branch Line extends as far as Newton. 
The Massachusetts Turnpike Extension, now under construction, 
will furnish Expressway service in this direction. 

North of Boston, railroad passenger service extends in sev- 
eral directions, and these lines carry the greatest number of rail 
commuters in the Boston area. Rapid transit service is maintained 
to the north by the MTA to Revere, Everett, and Cambridge; how- 
ever, these lines must be extended to provide adequate rapid 
transit service to the suburban communities, particularly if railroad 
commuter service is discontinued. The Northwest, Northern and 
Route 3 Expressways will provide vehicular traffic service for this 
northern area. 

IMPROVEMENTS TO THE MASS TRANSIT SYSTEM 

In 1959, the Massachusetts Legislature created the Mass 
Transportation Commission to study the extent and consequence of 
transportation problems, and in 1961 established a Special Legis- 
lative Recess Committee on Transportation to further this work. 
Previously in 1958, the Old Colony Area Transportation Commis- 
sion was established to study the critical transportation problems 
resulting from the then current threat of rail service abandonment 
in the area (which is now a fact) and a report thereon was pub- 



lished in April 1959, recommending rapid transit service. The 
South Shore Transportation District was established by the Legisla- 
ture in 1961 to provide rapid transit service between Boston and 
Braintree. 

In November 1960, the Mass Transportation Commission 
undertook, with federal assistance, a long-range study of the 
entire metropolitan transportation problem, and on January 30, 
1962, a report by the Joint Special Legislative Recess Committee 
was presented to the Legislature. A bill is currently before the 
Legislature providing for a Mass Transportation Commission pro- 
gram for planning and demonstration purposes. This program, 
among other related research matters, calls for traffic pattern 
studies, comprehensive origin and destination surveys, passenger 
attitude studies, rapid transit extension feasibility studies, and ex- 
periments on new types of equipment and related operational 
controls. 

The extent of past, present, and contemplated studies by the 
several agencies and others having interest in or jurisdiction over 
mass transportation facilities, is impressive. The generalized types 
of solutions developed in these studies are demonstrable evidence 
of the Commonwealth's responsiveness to the serious nature of the 
problem. Principal recommendations from earlier reports included 
the following rapid transit extensions: 

a. From the Ashmont MTA Station to Braintree or Brockton, 
with connections to Hingham and Whitman. 

b. From Sullivan Square to Reading and Reading Highlands 
over Boston & Maine tracks, via Maiden, Melrose, and 
Wakefield. 

Other mass transportation extension projects of the rapid- 
transit type, previously recommended, are the following: 

Forest Hills to Dedham-Needham 

Kenmore Square to Brighton-Newtonville 

Harvard Square to Waltham-Lexington 

Boston to Winchester-Woburn 

Revere to Lynn 

Every effort should be made, by responsible agencies, for 
integration of present and contemplated studies of mass trans- 
portation with the recommendations of this Study. 



1-2 



NNER BELT AND EXPRESSWAY SYSTEM 



PUBLIC 



NEEDS AND DESIRES 

The heavy volumes of traffic using the Central Artery, North- 
east Expressway, Southeast Expressway, Routes 2, 3, and 128, 
in addition to the traffic congestion on major arterial streets of 
the Metropolitan Area, are constant reminders to the commuter, 
businessman, and industrialist that the present partially-completed 
system for the transportation of people and commodities is grossly 
inadequate. Immediate relief of this congestion must be forth- 
coming to prevent utter traffic chaos and stagnation of the burgeon- 
ing business, industrial, institutional and residential development 
and redevelopment now in progress in the Metropolitan Area. No 
single factor will have a more profound effect on this development 
than completion of an adequately planned and properly designed 



Expressway System, integrated with complementing modes of 
transportation. 

The existing expressways provide an excellent example of 
the effects an expressway has upon travel desires in, and develop- 
ment of, the urban and suburban areas through which it passes. 
The extensive changes that have taken place in Massachusetts 
since the inception of the expressway construction program are 
conclusive proof that an expressway promotes growth, develop- 
ment, and progress in the communities served. Many areas of 
Metropolitan Boston have not as yet realized the advantages of 
the proximity of a modern expressway. A lagging rate of growth 
and development in these communities, as well as considerable 
traffic congestion on their arterial streets, in most instances can 
be attributed to the incomplete Expressway System. The majority 



of these communities recognize the need, and desire the unique 
advantages afforded those communities served by the completed 
sections of the Expressway System. 

The need for a modern highway system is supported by the 
knowledge that, as transportation services improve, business ac- 
tivity increases, accelerating development of the economic potential 
of the entire area, and resulting in a healthy, well-balanced family 
of communities. The desire is well established and the urgency 
for completion of this Expressway System is emphatically evident 
from the data and discussions contained in Traffic Analysis, Part III 
of this Report. Until the Expressway System is completed, a serious 
deficiency will exist in transportation facilities, thereby delaying 
progress, frustrating the desires, and abridging the potential of 
the Boston Metropolitan Area. 




tfSik* 



NNER BELT AND EXPRESSWAY SYSTEM 



1-3 



SECTION 2 -THE STUDY PROCEDURE 



The preparation of this Study included several interdependent 
subordinate investigations and studies. Much of the work was 
undertaken concurrently, and some work spanned the entire dura- 
tion of the Study. Detailed discussions of the procedures will be 
found in the relevant sections of this Study. The investigations and 
procedures, in their logical order, are as follows: 

a. A complete detailed review was made of all previous 
reports and highway location data pertinent to the Bos- 
ton Metropolitan Area. Consideration was given to all 
proposals and recommendations found therein, due re- 
gard being given to subsequent developments. 

b. Location controls, comprising the terminals of existing ex- 
pressways, topography, public and private institutions, 
general land use, railroads, major streets, existing street 
patterns, and feasible locations for interchange of traffic, 
were established. These controls, together with major 
traffic desires, essentially dictated the expressway loca- 
tions. 

c. Field reconnaissance of 25 miles of expressway corridors 
was undertaken. Particular attention was directed toward 
supplementing available records of the type, use and 
condition of dwellings, commercial and business estab- 
lishments. 

d. Available photogrammetric plans supplemented by aerial 
photographs, geological and subsurface data were ac- 
quired and studied. Street, utility, zoning, and proposed 
land-use plans were obtained from cities and towns for 
consideration of their effect on expressway location. 

e. An original and unique mathematical model was devised 
for the purpose of forecasting traffic volumes in 65 com- 
munities of the Traffic Study Area. Because conventional 
methods of forecasting traffic were considered inade- 
quate for the present purpose, extensive work was re- 
quired to develop this model for engineering application, 
based on land-use and sociological data. 

f . The study of the socio-economic effects of the Expressway 
System included 121 cities and towns in the region. Such 
factors as the overall economic base, shifting population, 



detailed employment trends, influence of zoning laws, and 
family incomes were all considered in this analysis. This 
Study included intense research work in development of 
satisfactory methods for the prediction of long-term func- 
tional benefits in advance of expressway construction. 
Numerous alternative locations were considered for each 
expressway. Each alternative was studied in plan and 
profile, prepared in conformance with established design 
criteria. 

Each alternative was evaluated with respect to right-of- 
way and construction costs, except in those cases where 
major disadvantages were so readily apparent that the 
location was discarded from further consideration. The 
right-of-way costs for each alternative involved establish- 
ment of the limits of construction on assessors' maps and 
determination of the street address, use, assessed value 
and fair market value for each parcel involved. Con- 
struction costs were tabulated under the major divisions 
of structures, earth work, pavement, utility relocations, 
and miscellaneous items and were developed by esti- 
mating the quantities of materials and applying unit 
prices which reflect current construction cost trends. 
Each alternative was then evaluated on the basis of 
ability to serve the traffic desires, its long-term functional 
advantages, socio-economic effect, compatibility with the 



surrounding area, effect on long-range community plan- 
ning, cost, and relative road-user benefits. 

j. Meetings with representatives of the Massachusetts De- 
partment of Public Works and the Bureau of Public 
Roads were held frequently for the purpose of assuring 
maximum coordination. 

k. In addition to these meetings, continuous liaison was main- 
tained with officials and representatives of interested 
business and civic groups. Briefings on the alternative 
Inner Belt locations were conducted in order to effect co- 
ordination between Urban Renewal Programs and plans 
for the Expressway System. Representatives of religious, 
medical, and educational institutions, and civic and public 
agencies, attended meetings held to discuss possible Inner 
Belt locations. 

I. An eleven-volume interim report was prepared and sub- 
mitted in February 1960. 

m. Public hearings were held in the spring of 1960 in Boston 
and Cambridge to provide the general public the op- 
portunity to review, criticize and otherwise comment on 
the feasible alternative locations that resulted from the 
extensive highway, traffic and socio-economic studies. 
The records of these meetings were reviewed and evalu- 
ated, and wherever practicable, were reflected in the 
subsequent selection of the Recommended and Alternate 
Locations. 




r.Vfc 



1-4 



INNER BELT AND EXPRESSWAY SYSTEM 





PART II 



EXPRESSWAY 

LOCATION AND DESIGN 

CONSIDERATIONS 



SECTION 1 - PHYSICAL LOCATION CONSIDERATIONS 



pOHt 



iC 



METROPOLITAN BOSTON 
EXPRESSWAY SYSTEM 

BACKGROUND AND DESCRIPTION 

The basic design and layout for the Inner Belt and Express- 
way System included in the scope of this Study are based on 
the concept of a system of radial expressways leading into the 
vicinity of downtown Boston from the suburbs, and terminating 
at a circumferential Inner Belt Expressway, as shown in Exhibit L-l . 
This Inner Belt will function as an inter-connector between the several 
radials and as a collector-distributor for traffic having its destina- 
tion or origin within the core area of Metropolitan Boston. This sys- 
tem of expressways was originally proposed in the 1948 Master 
Highway Plan. Sections of the expressway system proposed under 
the 1948 Plan have been constructed and are now in use. Other 
sections are presently being designed. Planning for the balance 
of the system, not yet constructed or under design, is the objec- 
tive of this Study. The necessity for completing the system is 
strongly emphasized throughout this Report. In addition, the sys- 
tem must be augmented by supplementary facilities and improve- 
ments in order to handle effectively the traffic volumes predicted 
for 1975, the design year. 

Sections of the expressway system of Metropolitan Boston 
have been designated as part of the National System of Interstate 
and Defense Highways, commonly called the Interstate System, 
as shown in Exhibit L-2. As such, they are an integral part of 
the nationwide network of limited-access highways that connect 
the principal metropolitan areas, cities and industrial centers, 
thereby contributing to the national defense. The Interstate Sys- 
tem . has been planned to interconnect the major population 
centers of the country with industry and defense establishments 
in such a manner as to insure that they are readily accessible 
by highways which offer a rapid, safe and dependable means 
of transportation. In the event of a national emergency, the 
Interstate Highway System will become one of the prime means 



Exhibit L-l 
METROPOLITAN EXPRESSWAY SYSTEM 




LEG_ENO 
STATE ROUTES 
US ROUTES 
INTERSTATE ROUTES 
EXISTING ROUTES 
EXISTING EXPRESSWAYS 
OTHER PROPOSED EXPRESSWAYS 
EXPRESSWAYS STUDIED 
TERMINAL CONTROL POINTS 



■ f~~ . :::!:':?$ CORE AREA 







MAP SCALE 



INNER BELT AND EXPRESSWAY SYSTEM 



I I - 1 







OCEAN 



50 50 100 15 200 
SCALE IN MILES 



NOTE 

SHOUT 5f>U» SECTIONS ANO ROUTES IN 

URBAN AREAS NOT SHOWN 



1 1-2 



Exhibit L-2 
NATIONAL SYSTEM OF INTERSTATE AND DEFENSE HIGHWAYS 



INNER BELT AND EXPRESSWAY SYSTEM 



PUBLIC 




COMPLETED INTERSTATE ROUTES 
PROPOSED INTERSTATE ROUTES 



for the distribution of personnel and materiel of war. 

Boston is the focal point of the Interstate System in New 
England, as shown in Exhibit L-3. This further accentuates the 
importance of the Inner Belt as an interconnector highway to 
distribute traffic from one interstate highway to another. This 
function is of prime importance in the shipment of raw materials 
to points of manufacture, manufactured goods to market, and 
the shipment of military supplies and defense materiel. All major 
defense establishments in Massachusetts are in close proximity 
to express highways, and the interconnection of these highways 
by the Inner Belt in Boston will provide a direct connection by 
way of limited-access expressways to these defense establish- 
ments. 

The expressway system as planned for Metropolitan Boston is 
analogous to a wheel, with Route 128, the circumferential highway, 
around the outer fringes of Metropolitan Boston as the rim, the 
Inner Belt as the hub, and the radial expressways as spokes of the 
wheel. Six radial expressways were proposed in the 1948 Master 
Highway Plan as follows: Southeast, Southwest, Western, North- 
west, Northern and Northeast Expressways. While changes and 
modifications have been made to the general plan as proposed by 
the Master Highway Plan, the basic concept of the radials remains 
the same. The essential function of the radials is to provide ex- 
pressway service to the various sectors of the Boston Metropolitan 
Area to the extent that all the major concentrations of population 
will be served by expressways which connect the core city with 
Route 128. Expressway capacity for all vehicular traffic desires 
cannot economically be provided. The cost of such facilities would 
be prohibitive, the concept would be impractical, and furthermore 
would involve the use of virtually the entire core area for express- 
way land takings and parking facilities. Therefore, the optimum 
number of radial expressways would simply provide expressway 
service to the major desire areas on the basis of geographical 
coverage, rather than provide a sufficient number of radial ex- 



Exhibit L-3 
INTERSTATE SYSTEM OF NEW ENGLAND 



NNER BELT AND EXPRESSWAY SYSTEM 



11-3 



pressways with capacity to satisfy the full desires of all vehicular 
traffic. 

The six radial expressways will serve all the major popula- 
tion concentrations of the Boston Metropolitan Area, and further- 
more will be so located that no point inside Route 1 28 will be 
more than three miles from an expressway, except in the Marble- 
head-Salem area. A lesser number of radials would not adequately 
serve the various population concentrations, and would result in 
an unbalance in the geographical coverage of each radial ex- 
pressway, since the locations of the Northeast Expressway, Northern 
Expressway, the Massachusetts Turnpike, and the Southeast Ex- 
pressway are now fixed. Additional radials would provide greater 
traffic capacity but at prohibitive cost as compared with alterna- 
tive methods of transportation. With improvements made to the 
mass transit system and to the arterial streets and parkways, the 
six radial expressways have the potential capacity to serve satis- 
factorily the vehicular desires of the area. 

COMPLETED PARTS OF THE EXPRESSWAY SYSTEM 

The parts of the expressway system, as proposed by the 
1948 Master Highway Plan, which have been completed and are 
now in use are as follows: 

a. The Central Artery, officially named the John F. Fitzgerald 
Expressway, is a major segment completed in 1959. This 
expressway extends from an interchange with the North- 
east Expressway, in the Boston and Maine Yards in 
Charlestown, through downtown Boston to a point in 
Roxbury at an interchange with the Southeast Express- 
way. The interchange with the Northeast Expressway 
is only partially completed and includes only that part 
of the interchange necessary to connect the two express- 
ways. The interchange with the Southeast Expressway 
is fully completed and the Inner Belt extension toward 
Roxbury functions now solely as local access to Massa- 
chusetts Avenue. 

b. The Southeast Expressway, from its interchange with the 
Central Artery to its interchange with Route 128 in Quincy 



and Braintree, and the extension of Route 128 to Hing- 
ham was completed in 1959. 

c. The Northeast Expressway from its interchange with the 
Central Artery to its interchange with Route C-l in Revere 
was completed in 1958; this section includes the Mystic 
River Bridge. The Northeast Expressway will be extended, 
as Interstate Route 95, in a new location to a connection 
with existing Interstate Route 95 in Danvers. 

d. The Northern Expressway from its interchange with Route 
128 to Salem Street in Medford was completed in 1961. 
The section of this expressway from Salem Street to 
Mystic Valley Parkway (Route 16) in Medford is presently 
under construction. 

e. The East Boston Expressway, connecting the Sumner and 
Callahan Tunnels in East Boston with Logan Airport and 
McClellan Highway, was completed in 1951, and is pro- 
grammed for extension as a limited-access facility to a 
connection with 1-95 in Saugus. 

f. The William F. Callahan Jr. Tunnel, the second tube of 
the Sumner Tunnel, connecting the Central Artery in Boston 
with the East Boston Expressway, was completed in 1961 . 

g. Route 128, the circumferential highway around the Boston 
, Metropolitan Area, was begun in 1948 and is now com- 
pleted from Gloucester on the North Shore to South Hing- 
ham on the South Shore. Its extension to a terminus at 
Hull is programmed for future construction. Parts of 
Route 128 which were originally constructed as a four- 
lane facility are now being widened. 

The parts of the expressway system which have been or are 
being designed are as follows: 

a. The Inner Belt from its interchange with the Northeast Ex- 
pressway and the Central Artery, including the balance 
of that interchange, to a point just south of the Prison 
Point Bridge. 

b. The extension of the Massachusetts Turnpike, functioning 
as the Western Expressway, from its present terminus at 
Route 128 in Weston to an interchange with the Central 
Artery at Broadway and Albany Streets. 



c. Route 2 from Route 128 to Alewife Brook Parkway. 

TERMINAL CONTROL POINTS 

-»*. Of primary importance to the layout of the proposed ex- 
pressways are the controls imposed by seven terminal control 
points resulting from existing construction and also from proposed 
construction for which the design has advanced beyond the pre- 
liminary planning stage. These seven terminal control points are 
indicated on Exhibit L-l as follows: 

W INNER BELT — The location of the existing terminus 
of the Central Artery at Massachusetts Avenue, in the Rox- 
bury section of Boston, just south of the Boston City Hospital 
and just west of its interchange with the Southeast Express- 
way. 

& INNER BELT — The location of the terminus of the 
segment of the Inner Belt which has been designed to a point 
just south of the Prison Point Bridge in the Boston and Maine 
Railroad Yard in Charlestown. 

& SOUTHWEST EXPRESSWAY — The location of the 
proposed interchange with Route 128, determined by pre- 
vious studies to be at a point just east of the Route 1 28 
crossing of the Neponset River. The Southwest Expressway, 
including this interchange, is under design south of Route 128. 

& NORTHWEST EXPRESSWAY (ROUTE 2) — The loca 
tion of the junction of Route 2 and Alewife Brook Parkway. 

ik ROUTE 3 — The location of the existing interchange 
of Route 3 with Route 128 in Burlington. 

& NORTHERN EXPRESSWAY — The location of the 
Northern Expressway at the Mystic Valley Parkway, Route 
16, in Medford now under construction. 

& MASSACHUSETTS TURNPIKE — The location of the 
proposed extension of the Massachusetts Turnpike along the 
New York Central Railroad into the railroad's Allston yards. 

Corridors of expressway locations were established in con- 
sideration of these terminal points. The locations of the existing 
terminal control points were predicated on planning which origi- 



II-4 



NNER BELT AND EXPRESSWAY SYSTEM 



B 



'C 



noted with the 1948 Master Highway Plan, and the corridors 
generally coincide with the expressway locations proposed by 
that Plan. 

The Inner Belt must be located so that it will serve the cen- 
tral core area of Metropolitan Boston, which includes areas in 
Boston, Brookline, Cambridge, Somerville, Everett and Chelsea, as 
shown on Exhibit L-l. The Inner Belt must also be large enough in 
diameter to provide sufficient length for the direct interchanges with 
the radial expressways and an adequate number of local street 
interchanges. Additional radial expressways would necessitate 
a larger-diameter Inner Belt in order to provide sufficient length 
for additional interchanges. With a larger-diameter Inner Belt, 
the local interchange ramps could not be favorably located with 
relation to traffic desires, and the resulting longer length of travel 
over the local streets would result in greater local street conges- 
tion. Therefore, the optimum location of the Inner Belt is one 
that will adequately serve the traffic desires and provide for 
the direct-connection radial interchanges and the local street inter- 
change ramps, with sufficient weaving distances between these 
points of access and egress. 

The widths of the several study corridors varied with respect 
to traffic desires, topography, institutional and general land use, 
and practical locations of the interchanges of the several radial 
expressways with the Inner Belt. Each of the above factors has 
been considered in the study of alternative locations for the Inner 
Belt and Expressway System. 



TOPOGRAPHIC CONTROLS 

TERRAIN FEATURES 

Major topographic features are important factors which must 
be considered in selection of expressway locations. The design 
criteria require gradual changes in direction, both horizontal and 
vertical, and therefore these features cannot be readily avoided. 
Topographic features in the Boston Metropolitan Area which have 
influenced the location of the expressways studied include, among 
others, the following: 



RIVERS 

Charles River, Mystic River and Neponset River. 

HILLS 

Highland Park, Parker Hill, Forest Hills, Bussey Hill, Brush Hill, 
Monterey Hill, Clarendon Hill, Little Blue Hill, Prospect Hill, 
Ten Hills, Turkey Hill, Follen Heights, Arlington Heights, 
Whipple Hill and Mt. Gilboa. 

PONDS AND LAKES 

Spy Pond, Upper and Lower Mystic Lakes and Fresh Pond. 

The effect of topographic features on location is discussed 
in Part V for each of the separate expressways. 

GEOLOGICAL DATA 

The geology of the Boston Metropolitan Area involves surficial 
and bedrock formations. Surficial geology consists of the over- 
burden atop the bedrock surface and varies in depth from zero 
at surface outcrops to approximately 250 feet below sea level in 
the study location areas. In these areas, the overburden materials 
existing from the buried rock floor upwards to ground surface 
consist generally of the following: 

a. Glacial till or boulder clay, or both, 

b. Glacial ground moraine of silt-to-gravel mixtures and 
boulders, 

c. Fluvio-glacial outwash, stream-deposited inorganic silts, 
sands and gravels in varying mixtures, 

d. Boston Blue Clay — a stratified, cohesive, sedimentary 
deposit of clays and silts of glacial origin, believed to 
have been deposited in a temporary glacial lake, 

e. Beach sands and other sands and gravels, 

f. Marine silt, muck, and peat, 

g. Filled land. 

The distribution of these sediments in both horizontal and 
vertical directions is of considerable complexity. The till, boulder 
clay, moraines and granular outwash formations and the Boston 
Blue Clay deposit are of glacial origin. Some were deposited 
directly by ice or in close proximity to the ice, and therefore are 
generally heterogeneous unstratified mixtures of clay-to-gravel 
sizes and boulders, a mixture called glacial till or hardpan. They 



are usually cemented and are very dense. Where the content 
of clay sizes is high, the till formation is often called boulder 
clay. The ground moraine is of somewhat similar origin. It is 
well-compacted but contains fewer fines and relatively more 
sand constituents and is generally uncemented. The outwash and 
morainal sands and gravel are well-sorted and stratified and 
are completely cohesionless. They usually occur in a relatively 
loose state of compaction. Beds of silt and fine sand frequently 
occur interstratified with the coarser sand and gravels. Beach 
sands and other sands and gravels occur in the coastal areas. 
The beach sands are derived from wave erosion and re-working 
of glacial till, forming the backbone of the many peninsulas de- 
fining the coast line. Due to the relatively large areas of sur- 
face layers of filled land, the extent of marine silt, muck, and 
peat is not clearly indicated. Much of the section adjoining the 
Charles River Basin has been reclaimed from inundated marsh 
land. 

The Boston area itself is dominated geologically by the Boston 
Basin, once the mouth of a pre-glacial stream which is now the 
Merrimac River. It is a deep, roughly saucer-shaped depression 
which has been filled with a thick bed of clay overlain in many 
places by a shallow layer of relatively dense granular material. 
This crust, however, is typically erratic and unpredictable. An 
important characteristic of the clay deposit is that its upper por- 
tion has been desiccated and oxidized, probably by a drawdown 
of the water table and atmospheric exposure during some time 
in the geologic past. This portion has a distinctive yellow-brown 
color, and is known locally as yellow clay. As a consequence 
of the drawdown the clay deposit on the surface is very stiff 
due to pre-consolidation, becoming gradually softer with increas- 
ing depth. The deeper clays have a blue-gray or olive-green 
color and have been described in soil-boring reports as being soft 
and plastic. 

Bedrock geology includes the various deposits forming the 
bedrock floor. These are highly consolidated by the previous 
effects of pressure or organic cementation or both. The bedrock 
geology in the Boston Basin consists of the following major forma- 
tions: 



INNER BELT AND EXPRESSWAY SYSTEM 



11-5 



a. Cambridge Argillite 

Cambridge Argillite is a formation consisting chiefly 
of rock of generally fine-grained argillaceous character 
that has been called shale and sand shale, argillite, and 
slate. The typical Cambridge slate is dark bluish-gray 
or brownish-gray, rather fine-grained, and composed 
chiefly of argillaceous material. Some parts of it are 
well-stratified and thin-bedded; other parts are rather 
massive. Most of it easily splits parallel to the bedding, 
and nearly everywhere it has developed a fissility across 
the bedding, but only rarely is the secondary structure 
dominant, and practically nowhere in the Basin is the rock 
a true slate. 

b. Roxbury Conglomerate 

The Roxbury Conglomerate is a highly variable 
formation, for in addition to the dominant conglomerate, 
it contains shale, slate, argillite, sandstone, quartzite, 
altered basalt and volcanic tuff. The conglomerate 
phase contains pebbles and boulders varying from an 
inch to a foot in diameter. The conglomerate is often 
exceedingly massive and it is frequently difficult to find 
any evidence of stratification. 

c. Mattapan Volcanics and Basement Complex 

The Mattapan Volcanics and Basement Complex 
consist of volcanic rocks of the carboniferous period, 
partly intrusive or extrusive or both, and partly sedimen- 
tary. The former are broadly classed as felsites and 
granite porphyry and melaphyre. The sedimentary rocks 
are predominantly tuffs, breccias and mud flows, de- 
posited in water courses and occasionally interbedded 
with conglomerates, sandstones and slates, also of vol- 
canic origin. The conglomerate and sandstone lenses of 
this formation are similar to the coarser Roxbury Con- 
glomerate formation described above. 
Outside of the Boston Basin the subsurface conditions are 
extremely variable and are discussed in Part V with reference 
to the expressway locations. Subsurface information collected for 
these studies are based on published data, particularly "Boring 



Data From Greater Boston," by the Boston Society of Civil Engi- 
neers, and on unpublished information from a variety of sources, 
primarily local boring contractors. This subsurface information 
available was adequate for basic design considerations. 



LAND-USE CONTROLS 

XJntegrated areas of land use have a greater effect on ex- 
pressway location than any other single factor. Their effective- 
ness as community assets would be adversely affected if the 
location of the expressway were such as to interfere with the 
integrity of integrated areas of land use. The purpose and function 
of the expressway is to provide increased vehicular accessibility 
for adjacent areas, and thereby to allow development of land to 
its highest potential. This purpose would be defeated if, in the 
process, the expressway were located so as to reduce the desir- 
ability of previously-developed large land-use complexes. 

Examples of land-use complexes which affect the location 
of the several expressways are parks and recreational areas, 











housing developments, hospitals, churches, educational institutions, 
large industrial, business, or commercial developments, established 
neighborhoods, and land in general which has been developed 
to its maximum potential. The effect of land-use complexes on 
location is discussed in detail for each of the separate express- 
ways in Part V. 



PUBLIC AND PRIVATE UTILITIES 

^ln the large, densely populated Boston Metropolitan Area 
there are many public and private utilities which are of vital im- 
portance. These utilities consist of sewers, storm drains, water 
mains, gas mains, telephone and electrical distribution lines, to- 
gether with rapid transit and railroad lines. These facilities are 
costly to relocate and therefore influence the location of express- 
ways. The locations of several of the major intercepting sewers 
of the Metropolitan District Commission and the City of Boston had 
a particularly important effect on the alternative expressway 
locations. 



-\ 



£ <N 







k 



3fc** N 



X 



*J^* 



II-6 



INNER BELT AND EXPRESSWAY SYSTEM 



SECTION 2 - DESIGN CONSIDERATIONS 



BASIC DESIGN CRITERIA 

A properly-designed urban expressway system comprises 
optimum features of traffic service, operational efficiency, econ- 
omy, aesthetics and safety. The design features adopted are 
consistent with the policies of the Federal Bureau of Public Roads 
and the Massachusetts Department of Public Works. A Policy 
on Arterial Highways in Urban Areas of the American Association 
of State Highway Officials, and Manual of Instructions for Prep- 
aration of Plans of the Massachusetts Department of Public Works 
have been used as guides in the preparation of the basic design 
of the expressways. The basic design criteria of the Inner Belt 
and Expressway System have been prepared in accordance with 
these policies and are shown in Table L- 1 . Controlling design 
speeds are as follows: 

DESIGN SPEED 50 mph — Inner Belt, radial expressways 
and direct connections, except segments of the Southwest 
Expressway and Route 3 immediately inside of Route 128, 
where a transition section permits a change in speed from 
the 70-mile - per-hour design speed outside Route 1 28 to 
a 50-mile-per-hour design speed inside Route 128. 

DESIGN SPEED 40 mph — Direct connections for the inter- 
change of the Inner Belt with the Massachusetts Turnpike, 
where toll booths preclude the necessity of a higher design 
speed. 

DESIGN SPEED 25 mph — Local access ramps. 



OTHER DESIGN FEATURES 

All the expressways included within the scope of this Study 
have been designed as controlled-access facilities, permitting ac- 
cess and egress at ramps only. The maximum number of travel 
lanes recommended for the Inner Belt and Expressway System 
is limited by economic and lane-efficiency factors. Eight travel 
lanes are generally recommended for each expressway with the 
exception that four lanes are recommended for Route 3 between 
Route 128 and its junction with Route 2. The number of travel 



lanes recommended and the design volume of traffic for each 
segment are shown on the Basic Design Exhibits for each ex- 
pressway. 

Recommended typical expressway cross-sections, Exhibits L-4 
and L-5, show the basic design elements and serve as the basis 
for estimating the costs of construction and acquisition of the 
right-of-way. It is recommended that 1 2 -foot travel lanes, 10-foot 
paved right shoulders and 4-foot paved left shoulders be pro- 
vided throughout the Expressway System. The use of a 10-foot 
paved right shoulder on tong bridges, viaducts and depressed 
sections is an exception to the policies governing the designs 
presented in this Study. However, experience in the operation 
of urban expressways carrying high traffic volumes has demon- 
strated the necessity of making this exception. Breakdowns which 
occur on the expressway at points where the paved shoulder 
has been omitted are responsible for materially reducing the 
expressway capacity and thereby causing serious traffic conges- 
tion. The basic designs and related cost data have been pre- 
pared on the basis of the use of 10-foot and 4-foot shoulders 
throughout the system. 

All ramps for local street interchanges are 22 feet in width 
to provide one travel lane in addition to space which would 
allow the storage of vehicles during peak use, provision to pass 
breakdowns, and for storage of snow under heavy snowfall con- 
ditions. 

The controlling vertical clearance for all expressways in- 
cluded in this Study is 14 feet 3 inches. However, subsequent to 
the adoption of this value, the Southwest Expressway was desig- 
nated as the route into the port of Boston which must provide 
16 feet of vertical clearance to meet military and defense require- 
ments. The 16-foot clearance could be provided at time of final 
design for the Southwest Expressway and would result in a slight 
increase in the construction cost. 

In urban areas essentially continuous frontage or collector- 
distributor roads, with a minimum of two travel lanes and a 
shoulder in each direction, are recommended as an integral part 
of the expressway system. The function of these roadways will be: 

a. To act as a feeder or collector-distributor system for the 



expressway itself, by augmenting the existing street sys- 
tem in the collection and distribution of traffic to and 
from the ramps of the expressway. This function of the 
frontage road system alone is of sufficient importance 
to justify their construction since in many instances traffic 
volumes to be handled by ramps exceed the traffic-han- 
dling capacity of adjoining existing streets without such 
frontage roads. 

To preserve the continuity of local streets cut off by the 
expressway, thus reducing the number of bridges other- 
wise necessary to maintain continuity, and to provide 
access to properties which otherwise would be denied 
access due to the expressway location. 







TABLE 


L-l 








DESIGN 


CRITERIA 














DESIGN SPEED 




Item 


50 mph 


40 mph 


25 mph 


Horizontal Curves: 














Radii*: 

Desirable, ft 
Desirable Minimum 
Absolute Minimum, 


, ft 
ft 






3,300 

1,000 

830 


500 


150 


Superelevation, Max., 


ft/ft 






.06 


.06 


.06 


Grades: 














Desirable Maximum 
Absolute Maximum 
Desirable Minimum 
Absolute Minimum 


! 






3.0% 
5.0% 

0.5% 
0.4% 


3.0% 
5.0% 
0.5% 
0.4% 


4.0% 
6.0% 

0.5% 

0.4% 


Vertical Curves: 














Curvature, K: 














Crests: 
Minimum 
Maximum 








80 

143 


50 

143 


30 

143 


Sags: 

Minimum 








100 


50 


40 



Three-centered compound curves for radii less than 3,300 feet. 



NNER BELT AND EXPRESSWAY SYSTEM 



II-7 



For Fills over 10 Feet 



ltf-0" 




3 Lanes - 36-0 



4 Lones - 48 -0 



12-0 



Typlcol Travel Lane 



l6'-0" Typical 



4-0' 



4-0 I 4-0" , 4-0 



Median 



3 Lanes - 36-0 " 



EXPRESSWAY 



4 Lanes - 48-0 " 



12"- 0' 



Typlcol Travel Lane 



10-0 





4'-0" 2 Lanes - 24-0" 



3 Lanes - 36 -0 



10-0 



DIRECT CONNECTOR 





Pier or Face of Wall 



3 Lanes — 36'-0" 



4 Lanes - 48 -0' 



^3-0 Offset to Walls when Length is over 200 Feet 
* 6'-0" Offset to Walls when Length Is 200 Feet or less 



FRONTAGE 
ROAD 




EXPRESSWAY , « * 

10-0 Width 



Varies 



4~9" , 



2-6T 



W**} 



4 



Width Varies 



|'-6" Min. __ 



22'-0" 1 



ONE LANE RAMP 




■*■ 3'-0" Offset to Wolls when Length is over 200 Feet 
*- 6'-0" Offset to Walls when Length is 200 Feet or less 




DEPRESSED EXPRESSWAY 

(HALF SECTION) 



2'-6" Safety Walk or 
6'-0" Sidewalk 



44-0" Min. without Median 



72-0 Min. with Median (2 Roadways at 34-0 and 4-0 Median) 



6-0' 



Sidewalk 



. , v : , , . — ^ 



—. — — ■ — — 



I — I — I — I — I — I — I — I 



3 



WALLED RAMP 



LOCAL STREET UNDER EXPRESSWAY 



LOCAL STREET OVER EXPRESSWAY 



11-8 



Exhibit L-4 
TYPICAL CROSS SECTIONS 



INNER BELT AND EXPRESSWAY SYSTEM 



PUBLIC 



£ 



RA 



r-6' 



10-0 



3 Lones —36-0 



4 Lones - 48 -0 



12-0 
Typical Travel 



16-0 



4'-0" 4'-0", 4-0" 4-0 



t Media 



3 Lones - 36-0 



4 Lanes - 48-0 



12-0 
Typical Travel 



Lane 



10-0 



4-1-6' 



r-e" 



2'-0" 



i i i i i i J i i i i i i i i l r rn 



2 Lanes - 24'-0 



3 Lanes - 36'-0' 






10-0' 



EXPRESSWAY VIADUCT 



i 1 1 I 1 1 j 

DIRECT CONNECTOR VIADUCT 



-1-6" 



10-0 



3 Lanes - 36-0 



2'-0" 




"-6 2'-0" 



i 



3 Lones - 36' -0 



4 Lanes 
Min. Clearance l4'-3" ' 



48'- 0" 



10-0 



I '-6' 



I 1 1 1 J 1 



Tunnel 

Symmetrical about <£ 




22-0 




1-6 



m - r— n 



ONE LANE RAMP VIADUCT 



TWO LEVEL VIADUCT 



EXPRESSWAY TUNNEL 




HIGH ABUTMENT 

OR 

WALLED SECTION 



* 6'-0" Offset to Walls when Length is 200 Feet or less 
in a Depressed Section. 

* 3'-0" Offset to Wotls when Length is more than 200 Feet 
in a Depressed Section. 



** Interstate Route 95-Mln. Clearance l6'-6' 



EMBANKMENT ABUTMENT 



EXPRESSWAY UNDERPASS 

(HALF SECTIONS) 



INNER BELT AND EXPRESSWAY SYSTEM 



Exhibit 1-5 
TYPICAL CROSS SECTIONS 



11-9 



c. To improve the expressway operation by providing ad- 
ditional capacity for traffic consisting of relatively shorter 
local trips than those assigned to the expressway. 
Lighting is recommended as a necessary safety measure for 
the entire Expressway System, including frontage roads, because 
of the high volumes of traffic utilizing the facility and the frequency 
of the location of interchanges. Landscaping of the expressway 
system is an important part of the initial expressway construction, 
and is considered as a functional as well as aesthetic factor. 



TRAFFIC CONSIDERATIONS 

EXPRESSWAY LOCATION 

The 1975 travel desires are based upon the completion of 
the transportation system and the anticipated economic growth 
of the Boston Metropolitan Area. To satisfy completely the future 
travel desires solely with the construction of additional express- 
ways would result in a prohibitively expensive and impractical 
system. The mass transportation system must be improved by 
the extension of present rapid transit lines and the addition of 
other lines, and improvements must be made to existing arterial 
streets in order to satisfy the transportation demands of the antici- 
pated growth of the area. Therefore, the traffic capacity pro- 
vided by the expressways represents only a partial fulfillment 
of all 1975 travel desires. 

The corridor of possible location of each of the expressways 
was established by the terminal control points which were set by 
previous study or existing construction. Since the forecasted travel 
desire in the corridor exceeds the expressway capacity, the as- 
signed traffic will reach capacity regardless of the location of 
the expressway, provided that: 

a. The locations within the corridor remain in areas of simi- 
lar land-use intensity. 

b. The locations do not vary sufficiently to overlap areas 
served by other expressways. 

c. The locations have interchanges which provide compa- 
rable local traffic service. 



The 1975 traffic assignments made to the various express- 
way networks verify the minimal effect of location on traffic 

volumes. 

EXPRESSWAY LOCATION WITH RESPECT TO MAJOR STREETS 
AND STREET PATTERNS 

" The expressway must be accessible via the existing street 
system and must be so located that maximum use may be made 
of major arterial streets in supplying and absorbing the express- 
way traffic. Even with provision for collector-distributor roads 
to distribute the traffic, congestion would be inevitable if the 
traffic could not readily be dispersed to major streets, since a 
single expressway ramp is capable of handling a greater volume 
of traffic than can be supplied or absorbed by most streets. There- 
fore, the expressway location with respect to major arterial streets, 
parkways, and the local street pattern, is an important considera- 
tion in determining its functional effectiveness. 

FREQUENCY AND RELATIVE LOCATION OF LOCAL RAMP 
SERVICE 

The number of ramps necessary for local street interchanges 



and their relative location was a major consideration in the analysis 
of alternative Inner Belt locations. There must be a sufficient num- 
ber of ramps so that the traffic desire does not exceed the ramp 
capacity, and the ramp location must be in reasonable proximity 
to the origin or destination of its assigned traffic. In addition, the 
location of the direct connections to the radial expressways further 
restricted the number and location of the local interchanges, due 
to the necessity of providing proper weaving distances to main- 
tain efficient operation of the expressway system. 

Sufficient information was obtained from the traffic assign- 
ment program for analysis of each ramp location and to make 
adjustments to meet the traffic desires. These adjustments were 
made consistent with factors which influence ramp location, par- 
ticularly the ability of the local streets adjacent to the express- 
way to accommodate the assigned ramp traffic, the provision 
of adequate weaving distances for operation, and the compara- 
tive costs of a ramp in different locations. 






■i i a &ss uM-* — t — *- v.r*T*r,*i^-^-JLi_JJ_j 



£& 



i if za ^ -_j _ ^HjgBJ— S 



•' _■ * ' 







11-10 



INNER BELT AND EXPRESSWAY SYSTEM 



SECTION 3 - ECONOMIC AND AESTHETIC CONSIDERATIONS 



PUBT. f C 



EFFECTS OF EXPRESSWAY LOCATION 

Urban expressway construction will inevitably have immedi- 
ate and long-term effects upon the structure of an area and the 
people who inhabit the area. Experience has shown that a lo- 
cation which is economically sound and otherwise highly advan- 
tageous to expressway users may temporarily disrupt a com- 
munity and its habitants unless proper precautions are taken to 
minimize such disruption. The evaluation of all conditions relat- 
ing to and resulting from proposed construction is absolutely neces- 
sary to permit the selection of that expressway location with maxi- 
mum potential for the community's long-range growth and de- 
velopment, and maximum benefits to the road-user consistent 
with the minimum adverse effect upon the communities involved. 
The road-user and non-road-user benefits of each expressway loca- 
tion must be weighed against its economic costs, and therefore the 
economic analysis involved consideration of physical effects, bene- 
fits to highway users, and construction, land acquisition, and main- 
tenance costs for alternative locations. 

The effects of the expressways studied were divided into 
two categories: physical effects and functional effects. The 
physical effects comprise the short-term effects of the highways 
as physical entities newly introduced into an existing urban en- 
vironment; the functional effects consist of the long-term benefits 
of the highways upon the growth and development of the com- 
munities in the Socio-Economic Study Area, with particular em- 
phasis on those communities in which the Inner Belt and Express- 
way System will be constructed. 

The physical and functional effects influence individuals and 
groups to highly variable degrees. These groups consist of 
local governments, residents, community groups, commercial and 
business interests, manufacturers, public services and others. The 
nature of the effects upon each group in each community was 
carefully analyzed. Since the objectives of the Socio-Economic 
Study involved advance determination of adverse short-term phys- 
ical effects, together with forecasts of beneficial long-term func- 
tional effects on community growth and development, it was 
inherent to the Study that equal consideration be given to each 
group in order to assure maximum future benefits for all. In 



the final analysis, emphasis was given to the opportunity for 
urban growth and development of each of the cities and towns 
affected by the expressway system. It was considered that this 
approach was most beneficial to the long-range interests of the 
general public. 

The physical effects had an important bearing on the selec- 
tion of the Recommended and Alternate Locations from among 
the numerous alternatives studied. Since construction of urban 
expressways requires land already in use for other purposes, 
the physical effects are primarily those relating to the displace- 
*v ment of existing land-users. The primary aim was to establish 
a framework around which the communities could plan a pattern 
of development which would capitalize on the improvement in 
transportation. 

The functional effects are similar for each expressway, be- 
cause all locations were in relatively narrow corridors with no 
appreciable difference in expressway travel times among the 
various locations studied. 

-^ Expressway construction of the magnitude contemplated in 
this Study will produce fundamental changes in the structure of 
the Boston Metropolitan Area. Changed time relationships among 
the cities and towns in the Study Area will result in concomitant 
changes in the location of future residential, commercial and in- 
dustrial developments. The Socio-Economic Analysis predicted the 
pattern of development for 1975, and then evaluated the effects 
of this development upon the various groups in the community. 



ROAD-USER BENEFITS 

The road-user benefit analysis is a method for evaluating 
the economic justification of new expressways. It provides a 
comparison of the relative value to the road-user of travel on 
an expressway as compared with travel on existing streets. The 
road-user benefit ratio is expressed as the ratio of annual road- 
user benefits obtained through the use of the expressway as 
related to the total annual costs of the expressway. This ratio 
has been computed for the Recommended and Alternate Loca- 



tions for each of the expressways, and the results are evaluated 
in Part V of this Study. 

The essential factors in the determination of a Road-User 
Benefit Ratio are outlined as follows:" 1 * 

a. Costs of construction and right-of-way for the express- 
way; 

b. Costs of maintenance and operation of expressways and 
their appurtenances; 

c. Direct benefits to road users in the form of reduced 
vehicle operating costs and saving in time by use of the 
expressway; 

d. Benefits to road users in the form of increased comfort 
and convenience; and 

e. Benefits to road users in the form of overall accident 
reduction. 

The formula for determining the Road-User Benefit Ratio 
follows: 



Benefit Ratio 



Annual Road-User Benefits 



Annual Costs 

Where 

Annual Road-User Benefits equal Annual Road-User Cost on 
Existing Streets minus Annual Road-User Costs via Expressway; 
Annual Costs equal Annual Project Cost plus Annual Main- 
tenance Cost for Expressway minus Annual Maintenance Cost 
for Existing Streets. 

The annual road-user costs for the expressways and exist- 
ing streets were determined by multiplying the following items: 
the traffic assigned thereto for 1975, the appropriate vehicle 
operating costs in cents per vehicle-mile, the length in miles of 
travel on either the expressway or existing street, and the days 
per year. 

The annual project cost consists of the amortized annual costs 
of construction and right-of-way. Demolition costs and engineer- 
ing and contingency costs were included as part of the construc- 
tion costs. 

•References will be found in the Appendix. 



INNER BELT AND EXPRESSWAY SYSTEM 



11-1 1 



In order to obtain amortized annual costs of construction 
and right-of-way and maintenance costs, Items a and b above, 
the following were assumed: 



TABLE L-ll 
VEHICLE COSTS PER MILE AT AVERAGE SPEEDS 



5% 

60 years 

40 years 
$20 / 000/mile 



Prevailing Interest Rate: 

Average Life of Right-of-Way: 

Average Life of Structure, Drainage and 

Pavement: 

Annual Maintenance Costs of Expressways: 

Annual Maintenance Costs of Existing Streets: $ 3,500/mile 

The cost units pertaining to Items (c), (d), and (e) were 
derived from two recent studies and an AASHO Report" 1 . In 
the determination of road-user benefits, two factors are: 

a. The average speed over the expressway and on the 
local street path serving the same origin and destination. 

b. The total vehicle operating cost per mile at the average 
speeds for expressway and street travel. 

From a travel-time study by Bone and Memmott 12 ', pertinent 
data as to average speed over existing expressways and com- 
parable local streets were selected for use in this Study as shown 
in Table L-ll. A study by Hoch' 31 presented detailed costs per 
vehicle-mile related to average speeds, as shown in Table L-ll, 



Expressway Speed 

Miles per hour 

30 

40 
45 



Local Street Speed 

Miles per Hour 

14 
20 
25 



Total Vehicle Cost 

Cents Per Vehicle Mile 

8.4 
6.7 
6.5 



17.0 
12.3 
10.0 



which costs include time costs, operating costs, and accident costs. 
The cost of stops was also reflected by the average speed; fuel 
consumption while idling was based on an estimate of 0.35 
minutes per stop. 



The completion of the proposed expressway system for 
the Boston Metropolitan Area will be justified by direct benefits 
to the motorist through lower vehicle operating costs, lower acci- 
dent rate, substantial time savings, and increased comfort and 
convenience. 

AESTHETIC CONSIDERATIONS 

Expressways were located with special consideration of the 
land-use patterns of the area to minimize disruption to the urban 
structure of the community and, where practicable, to provide 
an effective barrier between existing and proposed industrial 
and residential areas. Where practicable, the expressway sec- 
tion has been depressed to remove it from sight and reduce 
the noise level in surrounding areas. Construction cost estimates 
of expressway construction include landscaping and related work. 
Landscaping would be in harmony with the character of the high- 
way development and should be included in the initial construc- 
tion design. Effective roadside landscaping will benefit both the 
road-user and the roadside developments adjacent to the express- 
ways. An effectively landscaped expressway will aid in absorb- 
ing vehicular noises, screen the sight of moving traffic, and reduce 
headlight glare. 




^SL 



\ .. . _„. 




** tt 




T.S.K., 



11-12 



INNER BELT AND EXPRESSWAY SYSTEM 



SECTION 4 - PROJECT COST CONSIDERATIONS 



A 



1 D 



; To 



rp 



Pf'PMc 



GENERAL 

The project cost considerations comprise the construction 
costs, right-of-way costs, and other costs. Construction costs 
include all costs for the construction of the Expressway System 
and appurtenant work. Right-of-way costs include the costs for 
all land acquisition required to construct the Expressway System 
and appurtenant work. Other costs include the costs for demo- 
lition or clearance of the right-of-way, costs for engineering design 
and supervision, and a contingency allowance for project budget 
purposes. 

CONSTRUCTION COSTS 

The preliminary estimates of cost of construction have been 
prepared for the Recommended and Alternate Locations shown 
on the Basic Design Exhibits presented in Part V. Preliminary 
plans were developed at a large scale; the quantities of construc- 
tion materials were estimated on the basis of the type of con- 
struction indicated on these plans and profiles, and unit prices 
were applied to these quantities. The unit prices used for the var- 
ious construction materials reflect current trends in urban high- 
way construction costs. 

The total construction costs for the Expressway System in- 
clude all local-service ramps, frontage roads, and surface street 
improvements necessary for expressway operation to the extent 
shown on the Basic Design Exhibits. In addition, all miscellaneous 
items which affect construction costs are included. These items 
comprise utility relocation, lighting, signing, alteration of facilities 
such as rapid transit lines and railroads and maintenance of 
traffic thereon, railroad force accounts, temporary facilities for 
maintenance of street traffic, pumping facilities for sections de- 
pressed below existing gravity drains, and other appurtenant 
categories of work. All costs have been prepared based on con- 
struction in conformity with the design criteria presented herein. 
The construction costs are sub-divided geographically, for each 
expressway, and into major categories as follows: 

STRUCTURES: Viaduct, bridges, retaining walls, waterproofed 

depressed sections, culverts, tunnels, and appurtenant work. 



EARTHWORK: Rock, bridge and roadway excavation, and 

ordinary and gravel borrow. 

PAVEMENT: Sub-base, surfacing, roadway drainage, and 

looming and seeding. 

UTILITY RELOCATION: Relocation and alteration of all public 

utilities and surface drains. 

MISCELLANEOUS: All curbing, guard rails, lighting, signs, 

landscaping, and special problems such as alterations to 

rapid transit facilities and railroads. 

The estimates for the Recommended and Alternate Locations 
of the Inner Belt include the costs of the direct-connection inter- 
changes with the radial expressways. The limits of the estimates 
for the Inner Belt are the end of the permanent construction of 
the Central Artery, approximately 500 feet east of Massachusetts 
Avenue, and the end of the previously-designed section of the 
Inner Belt, in the Boston and Maine Railroad yard at Prison Point 
Bridge in Charlestown. The estimates include costs for the connec- 
tions to the Massachusetts Turnpike in the Allston yard of the New 
York Central Railroad. The limits of the estimates for the various 
radial expressways are as shown on the Basic Design Exhibits. 

RIGHT-OF-WAY COSTS 

The preliminary estimates of the cost of right-of-way acquisi- 
tion include the cost for acquisition of all land necessary to con- 
struct the facilities shown on each of the Basic Design Exhibits, 
including the land necessary to construct the ramps, frontage roads, 
and alteration of existing streets at the local interchanges. The 
estimates also include the cost for such easements as may be 
necessary to construct the expressway and its appurtenant struc- 
tures, and an allowance for severance damages in the case of 
partial takings. Wherever more than half a parcel was required, 
or wherever the remaining area of a parcel, regardless of its 
proportion to the whole, was left without a means of access to 
a public way, the value of the entire parcel was included in the 
estimate. Where a usable part of commercial structures of high 
value remained outside the taking line established, that part 
was not included in the estimate. An allowance was made for 



that part of the building taken, plus severance damages to com- 
pensate for the cost of alterations to the remaining part and for 
its diminished value. 

In order to arrive at an estimate of right-of-way costs, a 
limit of construction was first established on basic design plans 
for each expressway location, on the basis of recommended 
clearances between new construction and existing structures, with 
due regard for the conditions under which partial takings might 
be made. The limit of construction was then transferred to asses- 
sors' maps and adjusted, as necessary, to form a taking line to 
provide the proper clearances and space for construction pur- 
poses. When the taking lines had been established, city direc- 
tories, Sanborn maps, and assessors' records were used to obtain, 
for each parcel, information on its street address, assessors' plan 
number, block and lot number, parcel use, type of structure, 
number of dwelling units, tax status, area, assessed values of land 
and buildings, and total assessed value. To the assessed value, 
a ratio was then applied to arrive at the "fair market value." 

* Fair market value may be defined as the most probable 
price at which a well-informed buyer would be willing to pur- 
chase and at which a well-informed seller would be willing to sell. 
In order to establish such values for the right-of-way estimates, 
and to obtain an index of property values along the several 
routes under consideration, copies of the Banker and Tradesman, 
a weekly real-estate journal, were examined. This publication 
lists real-estate transfers in each municipality in Massachusetts 
by street address, and it indicates the value of the tax stamps 
used for the transaction. The sale price of the property was com- 
puted at a rate of $1.10 in tax per thousand dollars of trans- 
action. A sample of price variations was obtained by listing the 
sale prices and correlating these with the field survey reports to 
determine the use, size, type of construction, and condition of each 
sample. A field check of values was made to eliminate any dis- 
crepancies in this method of determining an indication of value. 
The results were then used to develop ratios of assessed value 
to fair market value for the City of Boston and the other cities 
and towns, as presented below. 



INNER BELT AND EXPRESSWAY SYSTEM 



11-13 



TABLE L-lll 

RATIOS OF FAIR MARKET VALUE TO ASSESSMENT 

CITY OF BOSTON 



Type of Use 


Range of Ratio: 




Single Family 


1.00 


to 


2.95 


Multi-Family 


0.706 


to 


2.59 


Apartment 


0.556 


to 


3.08 


Mercantile 


0.401 


to 


2.24 


Vacant Land 


0.692 


to 


2.94 



CITY OF BOSTON 

The extreme complexity of property value patterns within 
the corporate limits of the City of Boston, as compared with the 
usual pattern of single- and two-family dwellings predominating 
in surrounding communities, required a method of approach for 
the estimate of fair market value different from the procedure 
adopted in the other cities and towns. 

Some 528 sales listed in Banker and Tradesman between 
August 2, 1958 and January 2, 1960 were compared with as- 
sessed valuation, and ratios of fair market to assessed value 
were determined. A close examination of these data disclosed 
that there was an unusually wide variation in different sections 
of the City of Boston, and within certain districts a substantial 
differential existed among various classifications of properties. 
The expressway areas in Boston therefore were divided into nine 
sections, consisting of five along the Inner Belt and four along 
the Southwest Expressway. Each section contained five classifi- 
cations of property, each having a separate Fair Market Value 
Ratio. These classifications are Single-Family, Multi-Family (2 to 
6 families), Apartments (7 or more families), Vacant Land, and 
Mercantile. A range of the values obtained for the Fair Market 
Value Ratio for each classification of property in Boston appears 
in Table L-lll. 

The City of Boston has undertaken condemnation of certain 
unsafe structures together with demolition and clearing of land. 



v When an owner refuses to comply with demolition and clearing 
orders, title to the parcel is acquired by the City of Boston through 
appropriate legal procedures, and the City then effects the re- 
quired demolition and clearing. Since the value of such land is 
usually low, it may be utilized to economical advantage for ex- 
pressway purposes. In certain sections of Boston within the area 
of expressway location, such cleared land comprises up to 10% 
of the total area required for the expressway. 

OTHER CITIES AND TOWNS 

Approximately 1,400 sales listed in Banker and Tradesman 
between August 2, 1958 and January 2, 1960, were used to 
determine the ratios of assessed to fair market value for Brook- 
line, Cambridge, Somerville, Arlington, Lexington, Belmont, Med- 
ford, Winchester and Woburn. The structures and parcels in- 
cluded in the right-of-way cost estimates were divided into the 
same five categories used for Boston. In Cambridge, Somerville 
and Brookline, there were four times as many single- and multi- 
family structures compared to other types of structures. The lack 
of sufficient sales of all the types of structures to obtain a real- 
istic ratio in each city and town within the area of influence of 
the expressways necessitated the use of a single ratio for each 
of these cities and towns. 

In Arlington, Belmont, Lexington, Winchester and Woburn, 
the expressways pass essentially through recently-developed hous- 
ing areas, and the sales reported in Banker and Tradesman involve 
predominantly single-family homes sold by developers in these 
areas. A lack of sufficient sales of other types of properties, and 
the predominance of single- or multi-family structures taken, thus 
led to the development of a single ratio for each of these towns. 
In Canton and Milton, only vacant land would be acquired and 
most of the land required for the Southwest Expressway is in 
M.D.C. Reservations. In these cases, assessed valuations were 
doubled to estimate a fair market value without recourse to in- 
vestigations into recent real estate sales. In Burlington, all land 
necessary for the construction of the Route 3 Expressway has 
been acquired by the Commonwealth. The Fair Market Value 
Ratios used in obtaining fair market value from assessed valua- 



tions in these communities are shown in Table L-IV. 

OTHER COSTS 

DEMOLITION COSTS 

The cost of demolition was estimated on the basis of an 
evaluation of the type of construction of each structure. 

ENGINEERING COSTS AND CONTINGENCIES 

The costs of engineering design, supervision of construction, 
and contingencies were based on an allowance of 10% for en- 
gineering and 5% for contingencies, and were computed on the 
basis of 15% of the total cost of construction and demolition. 



TABLE L-IV 

RATIOS OF FAIR MARKET VALUE TO ASSESSMENT 

CITIES AND TOWNS OTHER THAN BOSTON 



City or Town 

Arlington 

Belmont 

Boston (Charlestown) 

Brookline 

Burlington 

Cambridge 

Canton 

Lexington 

Medford 

Milton 

Somerville 

Winchester 

Woburn 



Ratio 



2.70 

2.78 

1.45 

1.73 

Not Required 

1.76 

2.00 

2.50 

2.02 

2.00 

1.82 

2.56 

2.18 



11-14 



INNER BELT AND EXPRESSWAY SYSTEM 





PART III 



TRAFFIC ANALYSIS 



SECTION 1- INTRODUCTION 



u e 



Li 



{* 



ftAfCt 



PRIOR STUDIES 

Numerous published and unpublished traffic and highway 
planning reports were reviewed early in the present study. Of 
primary interest are three studies which span a period of thirty 
years and represent the more important highway and traffic studies 
of conditions in the Boston Metropolitan Area. These studies were 
reviewed in consideration of subsequent developments, including 
completed major highway projects and changed land-use patterns. 
These reports and surveys consisted of the following: 

a. Report on a Thoroughfare Plan for Boston (1930) 
(Origin and Destination Survey of 1927) 

b. Master Highway Plan for the Boston Metropolitan Area 
(1948) 

(Origin and Destination Survey of 1945) 

c. Report on Traffic Studies for the Boston Metropolitan Area 
(1957) 

(Origin and Destination Survey of 1955) 

Additional traffic and planning reports were reviewed, par- 
ticularly those directly related to specific portions of the study area. 
The Standard Metropolitan Area of 65 cities and towns, as defined 
by the 1950 census, was selected as the Traffic Study Area, as 
shown on Exhibit T-l, and is hereinafter referred to as the Study 
Area. 

Research and application phases of gravity model and traffic 
assignment procedures were also extensively studied. The projec- 
tions of traffic growth outlined in both the 1948 Master Highway 
Plan for the Boston Metropolitan Area and the 1957 Report on 
Traffic Studies, together with the assignment of traffic volumes to 
the expressway systems then proposed, were also reviewed and 
analyzed. 



Exhibit T-l 
THE TRAFFIC STUDY AREA 




INNER BELT AND EXPRESSWAY SYSTEM 




III-1 



REVIEW OF PREVIOUS REPORTS 

1930 REPORT ON A THOROUGHFARE PLAN FOR BOSTON 

The first comprehensive traffic study of record in the Boston 
Metropolitan Area was undertaken in 1927 and published in 1930. 
The report, prepared for the Boston City Planning Board by Robert 
Whitten, Consultant, was made with the cooperation of the Mayor's 
Street Traffic Advisory Board and the Division of Metropolitan Plan- 
ning, and presented the results of the first Origin and Destination 
(O. & D.) Survey conducted in the Boston Metropolitan Area. The 
traffic volume increase predicted in the 1930 report, for the period 
through 1959, coincides closely with the actual increase; the down- 
town cordon growth factor was predicted as 2.02 for the period 
1927-1959, whereas from recorded 1959 counts it was found to 
be 2.12. On the other hand, the 1945 downtown cordon growth 
factor (1.0), determined by survey, was actually far less than the 
1930 prediction (1.7). The depression of the early 1930's and the 
cessation of new car production during World War II, together with 
gasoline rationing, account for the recorded low vehicle travel 
growth from 1930 to 1945. These conditions offset what would 
have been an inevitable increase based on population expan- 
sion alone. 

An impressive feature of the 1930 report is the method em- 
ployed in the assignment of traffic volumes to a hypothetical high- 
way system. This highway system, illustrated in an exhibit contained 
therein, consists of a schematic design of radial and circumferential 
routes closely approximating what are now known as Route 1 28, 
the Inner Belt, and the Central Artery. Furthermore, the close re- 
semblance of the Whitten general traffic formula for "future 
inter-district" traffic to present-day traffic forecasting methods is 
remarkable. The 1930 data, while primarily of historical interest 
in the traffic field, was nevertheless reviewed and is briefly de- 
scribed here. 

The O. & D. study covered a total area comprising 39 cities 
and towns including the City of Boston, and consisted of "roadside 
interviews" at selected stations, a majority of which (105 out of 
178 locations) were within the City of Boston. Data for stations 
located outside of Boston is lacking. The survey and report period 
covered a wide range of economic conditions experienced in the 



boom days of the late 1920's and the depression period beginning 
in 1929 and 1930. In general, the data provided by this study 
was of little material use in connection with present-day statistical 
information. 

1948 MASTER HIGHWAY PLAN FOR THE BOSTON 
METROPOLITAN AREA 

The Master Highway Plan as developed in the 1948 report 
for the Boston Metropolitan Area is based upon the 1945 Origin 
and Destination Survey conducted by the Traffic Division of the 
Massachusetts Department of Public Works, in cooperation with 
the then Public Roads Administration, Federal Works Agency. The 
Boston Metropolitan Area covered by the 1945 survey comprised 
24 cities and towns which were subdivided into 138 zones. Zones 
in the Downtown Boston area were further subdivided into sectors, 
and the information collected in the survey from the home and 
roadside interviews was directly related to vehicular trips both origi- 
nating in and destined for each zone or sector, together with trips 
which passed through the external cordon stations. Traffic move- 
ments for all types of vehicles were thus obtained in 1945 for all 
station-to-station, station-to-zone, and zone-to-zone movements. 

The 1945 O. & D. Survey followed a procedure consisting of 
an Internal Survey (home, truck, and taxi interviews), and an Ex- 
ternal Survey (roadside interviews at external cordon points). A 
five per cent selected sample of homes was visited for the purpose 
of ascertaining travel habits. In the case of taxicabs and trucks, a 
ten percent sample was obtained by similar means. The external 
survey determined the travel habits of persons entering the study 
area. Simultaneously with the home interview phase of the survey, 
roadside interviews at 47 external cordon stations were conducted, 
accounting for 90 percent of all traffic entering or leaving the study 
area. The results of the internal and external interviews were later 
expanded to 100 percent on an average daily traffic basis, result- 
ing in a total of 811,053 motor vehicle trips through, into, and 
within the study area. 

1957 REPORT ON TRAFFIC STUDIES FOR THE 
BOSTON METROPOLITAN AREA 

A limited 1 955 Origin and Destination Survey was performed 



for the Department of Public Works, without federal participation, 
by the firm of Coverdale and Colpitts and was the basis of the 
1957 Report on Traffic Studies for the Boston Metropolitan Area. 
The objective of the 1955 O. & D. survey was the re-evaluation of 
the 1945 survey data for the primary purpose of examining, after 
10 years, the merits thereof in relation to uncompleted portions of 
the Master Highway Plan of 1948. In addition, the 1955 survey 
was planned so as to aid in evaluating a proposed Massachusetts 
Turnpike Extension into Downtown Boston, and to determine the 
feasibility of an additional harbor-crossing facility. 

The study area used for the 1955 O. & D. survey was the 
same as that for the 1945 study, but trip movement coverage had 
important variances. For instance, the 1955 interview data on 
zone-to-zone movements was limited to those movements between 
the northeast corridor and the downtown-southeast corridor; also, 
certain station-to-station and station-to-zone data covered in 1945 
were omitted in the 1955 survey. 

The 1955 O. & D. Survey consisted entirely of roadside inter- 
views which were conducted at 36 locations, 31 of which cor- 
responded with the 1945 external cordon-line stations. The 1945 
stations omitted were in the northeast and southeast quadrants of 
the 1945 study area; the 1955 survey substituted four new harbor- 
crossing stations, for the purpose of interviewing traffic using the 
Maiden, Wellington, and Mystic River bridges and the Sumner 
Tunnel, with respect to origins and destinations not only in Down- 
town Boston zones but also in cities and towns in the study area 
north and south of these crossings. A fifth new interview station 
was located on Route 128 at Winter Street in Waltham, in order 
to supplement data obtained at the 1945 stations in that vicinity. 
At the four harbor crossings, traffic was interviewed in both direc- 
tions but in only one direction at all other stations. 

INVENTORY OF AVAILABLE SURVEY DATA 

A detailed study of present and future vehicular traffic de- 
sires, based on available data, was undertaken in June 1959, in 
conjunction with the review of prior reports. Subsequent to the 
original 1927 O. & D. survey (39 cities and towns), other O. & D. 



1 1 1-2 



INNER BELT AND EXPRESSWAY SYSTEM 



A> 






surveys were conducted in 1945 and 1955 (both 24 cities and 
towns), as noted above. However, variations in the geographic 
scope, the study methods employed, prevailing national and local 
economic factors, and the overall purposes of each, precluded di- 
rect comparison of these surveys. 

Preliminary steps in the analytical procedures of this Study 
included a complete inventory of available data from both the 
1945 and 1955 O. & D. surveys. These data comprised informa- 
tion in punch-card and summary trip book form. The 1945 survey 
punch-cards had been consolidated, during the 1957 study, in a 
manner similar to the summary trip book compiled at the com- 
pletion of the 1945 survey. This consolidation resulted in a total of 
approximately 1 8,000 cards representing zone-to-zone and station- 
to-zone vehicular movements for only two classifications, passenger 
cars and trucks. 

The 1955 survey cards were in two groups, external stations 
and harbor-crossing stations, for a total of 230,000 cards repre- 
senting external zone to internal zone travel, and zone-to-zone 
travel between external and internal zones north and south of those 
stations using the harbor crossings. All 1955 card data were based 
on nine classifications of motor vehicles. Additional 1955 cards 
representing various analytical procedures were also inventoried 
and evaluated. The summary trip books, three for 1 945 and fifteen 
for 1955, contained print-outs of data punched on the foregoing 
cards. 

The 1945 survey covered area-wide zone-to-zone movements, 
and the 1955 survey produced similar data only at the harbor 
crossings, and those in limited form; therefore, only meager directly 
comparable 1945-1955 zone-to-zone data were available for use 
in this Study. In addition, while the 1955 survey was conducted 
under normal conditions, the 1 945 survey, one of the earlier O. & D. 
surveys undertaken in the nation, was made near the end of World 
War II, at which time traffic conditions were far from normal. Al- 
though the 1945 survey itself is entirely valid, the distribution, type, 
and volume of vehicle trips under continuing war-time restrictions 
on fuel and tires, and the shortage of vehicles, unquestionably re- 
sulted in a traffic pattern different from that to be expected under 
normal conditions. 



For the purpose of relating the 1945 and 1955 data to 1959 
traffic volumes as a basis for predicting 1975 traffic desires, an 
analytical procedure was developed to determine whether satisfac- 
tory results could be obtained by applying analogous growth-factor 
methbds to the data available from these two surveys. 

ANALYSIS OF AVAILABLE SURVEY DATA 

All cards and the summary trip books cited above were cross- 
checked to insure correct survey data comparisons. The differences 
in techniques and scope of the 1945 and 1955 surveys required 
complete regrouping of the 1955 data to develop conformity as 
closely as possible with the 1945 data for use in making trial com- 
parisons. This regrouping to effect direct comparisons was ac- 
complished in the following manner: 

a. The 1945 survey data cards were sorted by zone number 
in ascending order to provide a triangular matrix of zone- 
to-zone transfers and station-to-zone transfers; the num- 
ber of elements in this survey matrix totaled 8,204. 

b. The 1 955 survey data cards were sorted in the same man- 
ner, and an electronic computer was used to: 

(1) Consolidate the nine vehicle classifications into two. 

(2) Summarize the external zone-to-station movements. 

(3) Regroup Downtown Boston zone subdivisions to con- 
form with the 1945 survey coding. 

With the re-sorted and regrouped cards as input data, the 
computer was programmed to compute, compare and analyze 
1945-1955 ratios of traffic growth factors and traffic distribution 
patterns where applicable. The resulting comparisons are dis- 
cussed below. 

RESULTS OF TRIAL ANALYSES 

An analysis of the computed 1945-to-1955 trip transfer ratios 
indicated that a station-to-zone extrapolation was feasible and 
logical from the standpoint of zonal traffic growth and distribution. 
The growth of external stations likewise maintained, in general, 
reasonably consistent ratios. It was also found that zone-to-zone 



ratio comparisons, on the basis of grouped zones and also entire 
municipalities, approximated the traffic growth for comparable 
areas as checked by various cordon counts. For example, trip 
transfer ratios of movements between Downtown Boston and indi- 
vidual cities or towns to the north varied from 0.8 to 3.7, for an 
overall average growth factor of 2.2 for the years 1945-1955. 

On the other hand, individual zonal movement factors in this 
same area varied considerably due in part to the wide range of 
land-use and sociological changes over that same ten-year period 
within the separate cities or towns involved. The different survey 
techniques employed also accounted, in part, for these varia*ions. 
For these reasons, the possible use of the growth-factor method 
was considered in detail, resulting in the following conclusions: 

a. The inherent assumption that the previous level of service 
and travel patterns, in this case the restricted war-time 
travel of 1945, would be valid for projecting travel pat- 
terns to 1 975 comprised the major weakness in the growth- 
factor approach. 

b. The growth-factor method would require a complete and 
comprehensive O. & D. survey as basic input data; again 
this would require a direct dependence upon the 1945 
O. & D. survey which would reflect restricted war-time 
travel. 

c. The growth-factor method, requiring the projection of 
surveyed travel patterns into the future, would necessitate 
two growth-factor projections, i.e., one for 1945 to 1959, 
and one for 1959 to 1975. 

d. Only limited acceptable zone-to-zone ratios for the time 
period 1945 to 1955 were available. 

e. By the analogous growth-factor methods available at the 
time of initiation of this Study, where the base year zonal 
trip transfer volume was zero, the predicted future volume 
would remain zero; thus, the true growth of many of the 
outlying areas would not be reflected. 

f. Major changes in future land-use patterns as compared to 
the past would not be effectively taken into account by 
the growth-factor method. 

g. Because an expansion of the study area beyond the 1945 



INNER BELT AND EXPRESSWAY SYSTEM 



1 1 1-3 



study limit was proposed, an area would be involved in 

which no basic travel pattern data would be available for 

extrapolation. 

A complete socio-economic analysis would be required as 

part of this Study, which would also provide the input data 

necessary for a more advanced type of mathematical 

model. 



Certain aspects of the trial analyses substantiated a limited 
use of growth-factor forecasting methods for prediction of traffic 
into the near future. However, results expected from the use of this 
method applied to a 1 5-year forecast were considered inadequate 
in reflecting current and projected conditions in the area. The 
conventional growth-factor forecasting method was therefore dis- 



carded. A more advanced and sophisticated mathematical model 
was adopted, utilizing land-use and sociological data exclusively 
for prediction, and using the survey data only for calibration pur- 
poses. The application of this more advanced method required ex- 
tensive development under this Study. 







W.M, 



1 1 1-4 



NNER BELT AND EXPRESSWAY SYSTEM 



SECTION 2 -MATHEMATICAL MODELS FOR TRAFFIC ANALYSIS 



PUBLIC 



HISTORY AND BACKGROUND 

THE NEED FOR MATHEMATICAL MODELS 
IN HIGHWAY PLANNING 

Approximately three decades have elapsed since the home 
and roadside interview techniques and other sampling methods 
of making origin and destination (O. & D.) surveys in urban areas 
were first developed. The field methods used, the information 
obtained, and the method of presentation have changed very little 
since the earliest published survey. The original purpose of these 
surveys was to obtain field information that would be useful in the 
planning and improvement of highway facilities. However, since the 
data thus obtained reflected only current travel patterns, the prob- 
lem has always been to determine a satisfactory method of fore- 
casting future travel patterns and trip desires using not only O. & D. 
survey material but also socio-economic data. 

If compatible and thoroughly complete repeated O. & D. 
surveys were made at sufficiently close intervals, e.g., less than a 
decade apart, it would be possible to make reasonable short-term 
predictions of future traffic patterns from the O. & D. trip transfers 
alone by a method of extrapolating factors based upon various 
assumptions of analogous growth. ii4,n) * 

However, with no O. & D. survey data available, or if only 
one such complete survey has been made which gives a fairly 
complete picture of inter-area travel movements at some particular 
point in time, a recently developed and rationally more reliable 
technique may be used based upon the concepts of synthetic gen- 
eration and attraction of traffic by means of a mathematical model. 
In this case, the actual survey data may be used to establish the 
constants and parameters for a model and to verify and validate 
the general form of the assumed model. 

In the Inner Belt Study an attempt was made to determine 
present and future traffic movements based upon earlier survey 
data, particularly that of 1 945 and 1 955, by the analogous growth 
method. The results obtained were unsatisfactory and research 
was then undertaken to develop an effective mathematical model, 
the needs for which are summarized as follows: 

a. A suitable mathematical model or rational formula is re- 
*References will be found in the Appendix. 



quired whenever there is insufficient O. & D. data to es- 
tablish traffic patterns and trip desires. 

b. Without some rational model or logical technique, there 
is great difficulty in extrapolating into the future the 
presently available traffic data, although some credence 
might be given to short-term forecasting based on trend 
lines alone. 

c. Mathematical models can be effectively used to determine 
a complete matrix of present and future trip transfer 
volumes. 

d. In a large, complex urban area served by an extensive 
existing or proposed expressway system, mathematical 
models are highly desirable for assignment of both pres- 
ent and future traffic to present and proposed traffic 
facilities, and for investigation of the effects of design 
variations upon the resultant expressway assignments, 
such as route location within a corridor and specific ramp 
facilities. 

HISTORY OF POTENTIAL, GRAVITY AND 
INTERACTION MODELS 

The concept of a socio-economic gravity model began with 
the work of E. G. Ravenstein in 1885, (52) wherein it was observed 
that a population center tends to attract migrants from other cen- 
ters in direct proportion to its population size and in inverse pro- 
portion to its distance therefrom. Moreover, emigration from that 
area follows the same relationship. This has been called the "P/D 
relationship" or "population-divided-by-distance rule." 

More than thirty years ago this correlating principle was re- 
discovered by W. J. Reilly in connection with retail marketing and 
was called "the law of retail gravitation. " {27W) 

Reilly stated his law as follows: 

"Two cities attract retail trade . . . from an intermediate city 
or town in the vicinity of the breaking point, approximately 
in direct proportion to the population of the two cities and 
in inverse proportion to the square of the distances from these 
two cities to the intermediate town." (S4) 



Starting with the P/D rule, George Kingsley Zipf, a Harvard 
University philologist-sociologist, proposed in 1942 the following 
more general theory: 

". . . the number of persons that move between any two 
communities in the United States whose respective popula- 
tion are Pi and P2 and which are separated by the shortest 
transportation distance, D, will be proportionate to the ratio 
Pi P2/D, subject to the effect of modifying factors. " (7) 

Movement of materials by rail and motor freight, railway express 
and parcel post, bus passenger travel, newspaper circulation and 
telephone calls seem to follow this Pi P2/D hypothesis with fair 
to excellent correlation.' 78 8I1 

In an independent but coextensive work, John Q. Stewart, 
a Princeton astronomical physicist, extended his almost accidental 
discovery in 1941 of the application of the P/D rule to the geo- 
graphical attraction of college undergraduates into the concepts 
of "population potential," "demographic gravitation," and indeed 
into a whole system of "social physics." His work has been re- 
ported in a large number of publications. (6I6M 

This work of Zipf and Stewart was further integrated and 
generalized in work undertaken at the University of Washington 
Department of Sociology, in 1950, resulting in the formulation of a 
so-called "interactance hypothesis" by John A. Cavanaugh and 
Stuart C. Dodd. (22 ' 29) According to Dodd, the hypothesis of inter- 
actance predicts the number of interactions of any one specific 
kind among people, when observed in groups, from their basic 
dimensions of time, space, population and per capita activity. 
Groups of people interact more as they become faster, nearer, 
larger, and equalized in activity, and the number of interacting 
yet statistically independent entities clustered in each group con- 
stitutes the essential variable. This hypothesis includes the "PP/L" 
hypothesis, or population product over distance, and the popula- 
tion potential, or "P/L," hypothesis as special cases in which the 
remaining factors are unities. A condition held in the interactance 
hypothesis is that uniform density or an even distribution of the 
population exists over the area studied. This uniform density may 
hold even though the population may be clustered among human 



INNER BELT AND EXPRESSWAY SYSTEM 



II 1-5 



groups, such as cities of varying sizes, as long as all the groups 
of any one size tend to be evenly dispersed in the area studied; 
if the density is not uniform, then some function of the distance 
other than its first power may give a better fit between the model 
and the data. 

A completely independent outgrowth of the work of Raven- 
stein resulted in the 1940 promulgation by S. A. Stouffer of the 
"hypothesis of intervening opportunities." Since this novel and 
fresh insight still offers great promise for synthetic traffic move- 
ment models, it is worthwhile to quote the original hypothesis: 

". . . this hypothesis assumes ... no necessary relationship 
between mobility and distance ... It proposes that the 
number of persons going a given distance is directly pro- 
portional to the number of opportunities at that distance and 
inversely proportional to the number of intervening oppor- 
tunities. ,,,67) 

The law of intervening opportunities has already been applied 
with considerable success to problems in population migration. (IM0) 
Moreover, all mathematical gravity models can be shown to be 
merely special cases of this general law, involving particular as- 
sumptions with regard to the spatial distribution of the attract- 
ing opportunities, as indicated hereinafter. 

Another parallel development of importance stemmed from 
the discovery by Walter Christaller in the early 1930's of cer- 
tain empirical regularities in the distribution of population in South 
German cities.* 24 ' This work inspired A. Loesch to contribute to 
the foundations of the socio-economic science which has come 
to be called "location theory."' 43 ' 441 Together with the related 
fields of land use and the structure of metropolitan communities, 
these areas of study have accumulated a vast amount of litera- 
ture having a direct bearing on the problem of traffic analysis. The 
more important references are cited here.' 2 ' 3 ' 5 * 10 ' 25 - 27 ' 2 '' 30 ' 36 - 39 ' 46 ' 57 ' 68 ' 70 72) 

Two excellent reviews of the entire history of gravity and 
potential models are available in the papers of Gerald Car- 
rothers' 2 " and Willa Mylroie. (50) The former article contains an 
extensive bibliography. 

More recently there has been discussion and demonstration 
of the use of linear programming techniques for highway traffic 



estimation and projection. (4 ' 4, ' 64 ' 65) Linear programming is now a 
well-established mathematical technique for maximizing or mini- 
mizing a linear function of several variables, subject to certain 
constraints in the form of weak inequalities. Its use in the general 
area of transportation is now classic, but application to conven- 
tional highway traffic engineering has apparently just commenced. 

RECENT MATHEMATICAL MODELS 
FOR HIGHWAY TRAFFIC MOVEMENT 

INTRODUCTION 

Based upon the impressive heritage of fundamental and 
fruitful model concepts outlined previously, it was inevitable that 
significant applications would be made of gravity models and 
related ideas to traffic planning studies. 

These applications to traffic planning are still in the research 
phase; however, it appears that by use of suitable mathematical 
models and rational approaches, traffic forecasting and other 
aspects of urban planning are approaching the status of valid 
statistical scientific methods. 

Because these model techniques have not yet been fully de- 
veloped by others, the work involved in formulation of a mathe- 
matical model as required for the traffic analysis portion of the 
Inner Belt Study has to a great extent been of the research type, 
although every effort has been made to use available techniques 
compatible with sound engineering judgment. 

The mathematical model technique applied by others to the 
selected urban areas of San Diego, Baltimore, Chicago, Wash- 
ington, D.C., Boston (B.C. Seminar Studies), are discussed below. 
While all persons concerned with these programs were most co- 
operative in the exchange of technical information, there remained 
a distinct atmosphere of uncertainty and continuing experimenta- 
tion in this field. 

THE SAN DIEGO MODEL (l7 ' IM9) 

A traffic model was developed by the California Division 
of Highways under William B. Calland for the San Diego area 
for the purpose of designing the proper freeway system. The 
technique used employed both a gravity model for synthetic trip 



generation and distribution, as well as a routine diversion proce- 
dure for assignment of trip transfers to the proposed freeway 
network. 

The gravity model used states that the volume of trips from 
a zone of origin to a zone of destination is equal to the product 
of trip generation in the zone of origin times trip generation in 
the zone of destination times a travel friction factor. In equation 
form the inter-area formula would be written: 



V1-2 = KTiT 2 f 1-2 = KTi T 2 /d 



1.45 



where 



K 

V 



1-2 



T„ = 



1-2 



constant of proportionality, 
volume of trips with origin in zone 1 and des- 
tination in zone 2, 
trip generation in zone 1, 
trip generation in zone 2, 
1/d ' = travel friction factor, 



and 



d = airline distance in miles. 



Thus, the following points may be observed about this model: 

a. The attraction potential was taken identical to the trip 
generation. 

b. The separation effect was measured in terms of airline 
distance and neither route distance nor travel time were 
taken into account. 

c. The gravity exponent was taken for inter-zonal travel 
as 1.45 which is a mean value between one and two. 

d. The generated trips were manually balanced to fit screen- 
line and other survey checks. 

e. The distribution of trip transfers was carried out in an 
IBM 650 computer. 

f. It was necessary to readjust iteratively the gravitational 
constant K to force a balance of the total number of trip 
transfers with the trips generated. 

The future inter-zonal traffic obtained from this gravity model 
was then manually assigned to the network of present and future 
streets and proposed freeways, using the California time-distance 
diversion curve, discussed later. 



111-6 



NNER BELT AND EXPRESSWAY SYSTEM 






ftfiArt 



THE BALTIMORE TRANSPORTATION STUDY' 7477 ' 

In the Baltimore Transportation Study, under Alan M. Voor- 
hees, a multipurpose, multimode gravity model was developed. 
This model involved four trip purposes, namely work trips, com- 
mercial trips, social trips, and non-home-based trips. Moreover, 
attention was given separately to vehicle trips and mass transit trips. 

A rather complex and variegated procedure was used to 
compute the trips of each type generated within each zone. The 
destinations of these various types were then computed by means 
of a gravity attraction model based upon land-use statistics of 
the attracting area, together with the travel time between the 
destination area and the starting point of the trip. 

For mass transit travel, average transit time between zones 
was used, while for private vehicle trips auto travel time was 
employed. This effect of travel time on trip attraction was deter- 
mined by a set of tabulated, empirically-derived travel time fac- 
tors which were different for each of the four types of trip 
purpose. These travel time factors were then multiplied by the 
appropriate land-use attraction statistic to determine the total 
number of trips to be distributed to each zone. 

This model has been used for general long-range planning 
purposes, but to date it does not appear to be incorporated into 
an interdependent system with any comparable mechanized traffic 
assignment procedure, although the BPR assignment program was 
subsequently employed. 

THE CHICAGO AREA TRANSPORTATION STUDY' 4 ' 20 ' 

In the Chicago Area Transportation Study (CATS), an elab- 
orate program of total area transportation analysis and planning 
was undertaken by a team of experts under the overall super- 
vision of J. Douglas Carroll, and including Creighton, Campbell, 
Bevis, and others. 

As it applies to the present program the CATS studies in- 
clude two items of interest: 

a. The development of a traffic model to predict urban 
traffic volumes. 

b. The development of a method of assigning traffic to 
surface streets, as well as to express routes, and to 
rapid transit and surface transit facilities. 



The CATS traffic model involves a combination of conven- 
tional gravity model concepts and novel linear programming tech- 
niques. Linear programming was used in the CATS model to mini- 
mize inter-area travel frictions. It was necessary to require as 
programming constraints that all trips generated by a zone must 
be equal to all trips attracted from that zone, and that an inter- 
zonal transfer must be zero or a positive quantity, and not greater 
than a stipulated capacity measure. Two trip categories were used, 
residential and non-residential. As a result of the complexity of 
the technique employed it is difficult to express the inter-area travel 
formula for the CATS method in any reasonably concise equation. 
The procedure has been checked against O. & D. survey data, 
using trip length comparisons and correlation coefficients. The 
model was compared with a more conventional type of gravity 
model using a sample of 3600 inter-zonal movements. The CATS 
model was reported, on comparison with the O. & D. data, to 
have a correlation coefficient of 89 per cent, compared to 78 per 
cent for the comparable gravity model. 

In the Chicago Area Transportation Study a mathematical 
program was developed for the IBM 704 computer for assigning 
zone-to-zone movements to a complete urban highway network, as- 
suming a minimum travel time basis. The method finally selected 
for an assignment program for the Chicago area was based on 
considerable research by CATS and others. This method is pri- 
marily based upon the concept of building minimum-time-path 
trees from a representation of the street network as discussed 
later. A number of important points may be made concerning 
this approach: 

a. It assumes and employs the "all-or-none" method pre- 
sumably supplanting the customary diversion curves. 

b. The use of the all-or-none method is found to be both 
necessary and surprisingly accurate when the volume of 
movements and density of the streets is sufficiently great. 

c. The assignment program may be modified, albeit at 
great cost, to include the effects of route loading and 
capacity, which accounts for the principal effects of the 
diversion curve. 

As mentioned, this assignment program was designed for 
execution by means of electronic data processing machines. 



THE BUREAU OF PUBLIC ROADS MODELS AND PROGRAMS' 16 ' 45 ' 
The Bureau of Public Roads carried out a program of re- 
search activities in the application of gravity models to inter-area 
travel and in the development of machine assignment procedures. 
The gravity inter-area travel formula used by the Bureau for home- 
based trips may be expressed as follows: 

T ..-/p.Aj +p .Ai\ K 



A 



A/ D 



u 



where T;j = 

Pi and Pj = 

Aj and Aj = 

A = 

Dii = 

K = 

and n = 



the total number of primary trips between zones 
i and j, i.e., with one end at home, 

the number of primary trips produced in zones 
i and j by residents of these zones, 

the number of primary trips attracted to zones 
i and j by non-residents plus inter-zone trips by 
residents of those zones, 
the number of primary trips attracted to all zones, 

the distance between zones i and j, generally 
expressed in terms of travel time, 

a constant | both to be determined empirically 
an exponent I from the analysis. 



This formula and a similar one for secondary non-home based 
trips, are being evaluated by the Bureau using an IBM 704 against 
the Washington Metropolitan Area 1 948 and 1 955 O. & D. surveys. 
For trips produced, P, and attracted, A, actual survey values are 
used, and the test involved is merely to determine whether any 
such formula as this will produce reliable results, and, if so, what 
are the corresponding values of K and n. A program has also been 
undertaken by the Bureau to relate the P and A factors to land- 
use statistics. 

The Bureau's program for the assignment of traffic to a high- 
way network, reported by Glenn E. Brokke, was based upon a 
time-ratio concept. With the collaboration of the General Elec- 
tric Computer Division in Phoenix, Arizona, it was programmed for 
solution by an IBM 704. This technique employs the same mini- 
mum-time-path principle used in the CATS studies, the Detroit 



INNER BELT AND EXPRESSWAY SYSTEM 



III-7 



studies, and in this Study. The assignment is on an "all-or-none" 
basis but with a diversion between two networks, and capacity 
limitations have to be accounted for by iterative reductions in 
travel time. The Washington program was amended and revised 
to account for turning movements. 

THE BOSTON COLLEGE SEMINAR RESEARCH BUREAU 1691 

Investigations of current gravity model projects included that 
of the recent Boston College Seminar Research Bureau project. 
The Boston College technique is based on a selected home inter- 
view sample (1000 interviews throughout the Boston metropolitan 
area which were later expanded statistically) to represent a metro- 
politan area of 100 cities and towns. Trip frequencies in each 
of 100 cities and towns of origin on the basis of five purpose 
categories, were estimated on the basis of 100 interviews in each 
of ten selected municipalities. These trip origins, generated on 
this sample basis are then distributed to trip destinations using 
an inter-area travel formula programmed for an IBM 650 elec- 
tronic computer. 

GENERAL CRITICISMS 

In view of the aspect of continuing experimentation exempli- 
fied in the applications cited, it became apparent that if a gravity 
model were to be used at all, a new, original, sound and scientific 
approach to the engineering requirements of this Study would be 
mandatory. This new approach, it was recognized, would be re- 
quired to take into account the following factors: 

a. The objective of this Study was the planning, location, 
and basic design of the Inner Belt and Expressway Sys- 
tem, and neither an urban area traffic study in itself, nor 
research and development of advanced traffic analysis 
techniques. 

b. Although thus limited in objective, the accompanying traf- 
fic analysis, in order to arrive at meaningful results, must 
take into account the effects on these expressways of 
all traffic activity in the Boston urban area. 

c. The scope of the usage of the mathematical model being 
thus bounded, the model as an engineering tool must en- 



compass the entire traffic problem in as brief and 
straightforward a method as possible. 

RECENT DIVERSION PROCEDURES 

INTRODUCTION 

After a complete transfer matrix either for present or for 
future inter-area trip movements has been determined, it is then 
necessary to estimate the loading of these trips onto the expressway 
network. In order to accomplish this objective, some rational meth- 
od for assigning traffic to the alternative routes is required. This 
process involves the use of a distribution relationship or diversion 
curve as outlined below. 

CURRENTLY USED DIVERSION CURVES AND FORMULAE 

Several types of diversion relations are now in current use, 
such as the following: 

a. The time-ratio curve in the BPR "Guide for Forecasting 
Traffic on the Interstate System" of October 15, 1956. 

b. The distance-ratio and speed-ratio curves used in the 
Detroit studies. 

c. The time-and-distance differential curve used in the Cali- 
fornia studies. 

d. The so-called "all-or-none" law. 

The first three of these methods have been discussed by 
Glenn Brokke: 

a. "The Bureau's time-ratio curve relates the percentage of 
trips using a freeway facility based on the ratio of the 
travel time via the freeway to the travel time via the best 
alternate route." 

b. "The speed-ratio curves developed for the Detroit Area 
Transportation Study consist of a family of curves where 
the percentage of freeway use is related to speed ratio 
and distance ratio. Because these curves represent a 
three-dimensional surface with an undefined mathemati- 
cal relationship, they are difficult to use in a computer 
application." 

c. "The California time-and-distance curve consists of a 
family of hyperbolas where equal time and distance on 



the freeway as compared to the best alternate route 
will assign 50 per cent of the traffic to the freeway."' 161 

Thus all presently used assignment procedures employ no 
more than two times, Di, D2, and the corresponding two distances, 
di, di. These then assume a general diversion relation of the form: 

P = Function of (D x , D 2 , di, d 2 ) 

where P = fraction of traffic assigned to the expressway or 

principal route (subscript 1), 
1-P = fraction assigned to the other single alternative 
mode or path (subscript 2), 
D = time on a route or path, 
and d = distance on a route or path. 

The Detroit empirical diversion relation is based on the time 
ratio Di/Dz and distance ratio di/dz, and therefore can be repre- 
sented in the form: 

P = Function of (Di/D 2 , di/d 2 ) 

The California diversion as well as several others which have been 
employed in the past are based upon the time saved or time dif- 
ference Dz minus Di, and distance saved or distance difference 62 
minus d>. These diversion relations would take the form: 

p = Function of (D 2 -Di, d 2 -di) 

The simplest of the above three cited practices is the Bureau 
(Washington) curve which assumes that diversion is insensitive to 
distance and merely depends upon time-ratio alone in the form: 

P = Function of (Dt/D 2 ) 

However, for many purposes of computation, especially where 
a large number of movements are involved and where either cor- 
ridor traffic or free assignment traffic (i.e., without capacity re- 
striction) is desired, the so-called "all-or-none" time diversion law 
may be used, where either the difference form, 



r 2 



(d 2 -i)i) + 1p2-eh1 



|D 2 -Di| 



I 11-8 



NNER BELT AND EXPRESSWAY SYSTEM 



o 



&i 



c 



Li 



or the ratio form, 



P = 



1 + 



1-(D 1 /D 2 ) 

l-(Di/D 2 )l 



may be adopted, yielding the same results whether based on time 
ratio or time difference. This formula, which merely assumes that 
all traffic is diverted to the quickest path, is illustrated in Exhibit 
T-2, and may be considered the limiting case for any number of 
similar S-shaped curves. 

GENERAL CRITICISMS 

Any rational method of assigning traffic movements to an 
expressway network overlaying a complex street pattern should 
take account of the fact that any given movement will actually 
be distributed over a large number of possible paths between the 
two trip ends. The only regularization principle which orders this 
otherwise chaotic system is that with large numbers of individual 
movements there is both a logical and a measurable tendency 
to have a greater fraction of the given movement travel over the 
quicker or shorter paths. 

The National Policy of the American Association of State 
Highway Officials' 51 ' recommends for assignment the use of a diver- 
sion curve displayed therein, based on Highway Research Bulletin 
No. 61, "Traffic Assignment," 1952, cited in a footnote thereto. 
Research of the technical literature concerning assignment proce- 
dures revealed that considerable work had been accomplished 
in this field since the publication of that Bulletin. (l6 ' l9,47 ' 58 ' 73) 

Several investigators have engaged in refinement or altera- 
tion of the original diversion curves to accommodate particular 
situations. (IS ' 73 ' Probably the most significant findings, however, are: 
a. "Those who have advocated diversion curves for use in 
traffic assignment have done so to meet the requirements 
of designers who ask the traffic engineer to tell them 
how many vehicles will use a ramp or a facility in the 
peak hours. The use of these empirical curves may be use- 
ful for such assignments to an already determined line. 
"But it is also possible that diversion curves are wrong. 
They have been established by making observation of 



an existing system's usage. Naturally, such systems tend 
to be in traffic equilibrium — that is, 'traffic seeks its 
own level.' It follows, therefore, that diversion rates are 
a function of the capacities and traffic pressures in the 
region being examined. If the expressway being meas- 
ured for diversion had either fewer or more lanes, it 



TIME RATIO TRAFFIC DIVERSION CURVES FOR FREEWAYS 


100 






90 


ssses, 


**5 
























80 




N 


^ 




1 
K 




LEGEND 

p^ STATE OF MISSOURI 
(KANSAS CITY) 

ALL OR NONE 

AASHO 

— ™ BPR (PASSENGER CARS) 










^ 


k 


-J 

S 














% 
V 
















50% 


USAGE 




> 


^ 
























N\ 












10 















\ \ 


\ 






















< 


\ 
\ 






















\ 


^ 


\ 






















■\ 


^ 


^"^ 
*"***^ 




_i 1 1 1 1 1 .( „■„.!. n -—■■■■■—! "."' i" 1 ^-"-— ■(-"•.■'■' i 

0.4 5 6 0.7 0.8 0.9 1.0 U t.2 1.3 1.4 1.5 1.6 

TRAVEL TIME RATIO 
{TIME VIA FREEWAY / TIME VIA QUICKEST ALTERNATE ROUTE ) 



Exhibit T-2 

seems quite clear that correspondingly greater or less 
traffic would use it and, therefore, diversion rates would 
change . . . 

"In sum, there are quite apparent and inherent weak- 
nesses in diversion curves as they are developed and 
used today. One of the greatest is that such curves 
provide an answer which is unrealistic by definition and 
yet is assumed to be correct. Therefore, the analyst does 
not truly know what he has obtained because the elabo- 



rate construction of the diversion curve merely produces 
an answer . . . 

"A simulation of traffic flow would, if properly done, 
produce a result identical with the current usage of the 
urban network. In other words, the result of accurate 
flow simulation would be a current traffic flow map . . . 

"To the planner, then, the extent of driver diversion 
is not visible on a traffic flow map and it is quite diffi- 
cult to read the need for improved routes where the 
overloads are evenly distributed throughout the system. 
In short, needs cannot be determined by reading a traffic 
flow map. It is precisely for this reason that origin-des- 
tination data were collected. 

"It is possible to confuse a request for realism with 
traffic assignment as it can be of use to the planner. 
The planner needs to know where an improvement in 
capacity will do the most good. This method of traffic 
assignment by being 'unrealistic' is able to magnify the 
points of great system stress and thus insure most judi- 
cious placement of improvements. 

"Also, when a plan is finalized, this method can be 
modified so that capacity restraints are introduced to 
the network and trips are diverted from congested to 
alternate routes, thus more realistically simulating pre- 
dicted usage. In this fashion, capacities can be dealt 
with explicitly and the extent of diversion caused by 
capacity constraints can be measured. It is of substan- 
tial interest to note that this cannot be achieved by di- 
version curves. They are not sensitive to capacity con- 
straints excepting those which were in effect when these 
curves were empirically established. " (20) 

"I have previously discussed the 'All or Nothing' and 
'Diversion Curve' methods and mentioned that we used 
both methods in every one of our assignments. We have 
now concluded that in a densely populated large urban 
area with a comprehensive freeway system offering many 
alternative freeway routings, that the 'All or Nothing' 
method is the most practical method to use." ( " ) 



INNER BELT AND EXPRESSWAY SYSTEM 



II 1-9 



THE MODEL 

INTRODUCTION 

As is evident from the foregoing discussion of the history 
and background of mathematical models, the problem of repre- 
senting traffic in a mathematical model consists of three distinct 
but more or less interdependent phases, namely traffic generation, 
distribution, and assignment. 

a. Traffic generation is concerned with the questions of 
what gives rise to traffic; that is, in any given portion 
or zone of an urban area, how much traffic is originated 
by the people, plant, and activities which are unique 
to that zone. 

b. Traffic distribution is concerned with the question of where 
that generated traffic desires to go; that is, of the traffic 
generated in that zone, how much is attracted to each 
of the other zones of the urban area by virtue of the 
people, plant, and activities unique to each of the other 
zones. 

c. Traffic assignment is concerned with the question of the 
routes which traffic will take, or will desire to take, when 
the generating zones, or origins, and attracting zones, or 
destinations, are known for all fractions of the urban 
traffic. 

The generation of traffic to be ascribed to each zone may 
be based upon an origin-destination field study, the projection 
of values obtained from such a study, or upon independently- 
determined sociological data. The distribution of such generated 
traffic is dependent primarily upon two factors, the relative at- 
tractiveness of each zone for the traffic generated in any zone, 
and the relative geographic separation of the zones. The assign- 
ment of traffic must be based upon some measure of the relative 
merit of the several possible routes between any two zones. Mathe- 
matical investigation reveals, as explained below, that the prob- 
lems of relative separation of zones, and of relative merit of 
routes between zones, can both be solved in a single analysis, 
an indication of the aforementioned interdependence. 



THE NEED FOR A SINGLE-PURPOSE MODEL 

As discussed previously, all prior and current traffic models 
for various reasons were deemed too complicated and unsuitable 
for the present purposes. It is important to reiterate that most 
of the currently used gravity traffic models are still very much 
in the research phase. Particularly in the case of those employed 
by Voorhees, 174 77) these are multimode, multipurpose models which 
deal separately with all modes of travel and transit and with all 
major trip purposes. To establish a model of such complexity, which 
would be particularly suited to the Boston area, was not within the 
scope of this Study. Neither was it considered feasible to employ 
an existing model specifically developed for another area. The 
principal objectives, therefore, were to: 

a. Develop a new and simple model which would in a single 
mathematical system: 

(1 ) Generate realistic synthetic trip transfer volumes 
solely from sociological and land-use data, without re- 
course to sampling in the base year. 

(2) Distribute this traffic to various zones of attraction 
solely on the basis of travel times and sociological and 
land-use data. 

(3) Mechanically assign the resultant computed trip trans- 
fers to suitably represented street networks and express- 
way systems. 

b. Develop a model which would satisfy all the above con- 
ditions and which could be programmed for a large- 
scale electronic computer. 

It was decided, based on these observations, to develop such 
an original model. Since this Study contained no provision for either 
experimental development of this nature nor a continuing, long-run 
investigation, it became mandatory to establish a stark and clear- 
cut procedure. Thus the model finally adopted employed simplifi- 
cations which were judged to be entirely consonant with the objec- 
tives previously cited. 

MINIMUM TIME PATHS THROUGH THE HIGHWAY NETWORK 

INTRODUCTION 

Exclusive of major arterial streets and expressways, there 



exist well over 50,000 individual street links in the Boston Metro- 
politan Area. It is inconceivable that such a large and randomly 
oriented network could be represented in complete detail for traffic 
flow analysis. Therefore, a suitably skeletonized network was de- 
vised to serve as an equivalent street network, although the express- 
way network together with accompanying ramp facilities was rep- 
resented in strict one-to-one detail. These techniques are discussed 
below. 

THE DEFINITION OF A NETWORK 

By a NETWORK in this report is meant an interconnected 
system of paths consisting of intersection points called NODES 
joined by individual route paths called LINKS. The nodes are de- 
fined and specified by means of their X-Y coordinates on the 
Massachusetts Grid System. 

The links are given directional sense such that link ij joining 
node i to node j is not the same as link ji joining node j to node i. 
Each such unidirectional link is defined and specified by means 
of the coordinates of each of its terminals in the fashion: 

LINK ij = [(Xi, Y0, (X Jf Yj)] 

LINK ji=[(Xj, Yj), (X, Yi)] 

The DISTANCE of each and every link can be computed in 
terms of the square root of the sums of the squares of its co- 
ordinate differences in the form: 



di j =v / (X i - Xj) 2 + (Yi - Yif 

With a definite value of SPEED, Vij, assigned to each link, 
it is then possible to determine a specific value of LINK TRAVEL 
TIME, Dm, in the fashion: 

i>— 4l 

A complete network description can always be given in terms 
of the set of all NODES-PLUS-NODE-NEIGHBORS. The NEIGHBOR 
NODES adjacent to each node are all those points which can be 
reached from it over a single existing link. Thus a set of node- 



III-IO 



NNER BELT AND EXPRESSWAY SYSTEM 



•pos- 



c 



tj 



plus-neighbors defines a STAR of radial links which may be rep 
resented in coordinate fashion: 



NODE: (Xj.Yj) :(X B ,Y, 

(X b ,Y b ) 

(X c ,Y c )}NODE NEIGHBORS 



(X n ,Y n ) 

Any movement over this star will always be assumed to be 
radial outward for directional sense. That is: 



a- 1 



n 

Thus the set of stars originating from each and every node 
specifies all possible movements over existing network links. 

Any route or PATH through the network can be described 
by specifying the chain of ordered coordinates defining the NODES- 
ON-ROUTE. This gives a representation for the path ij in the form: 



u 



J 



(X 5l Yi) (X U ,Y U ) (X V ,Y V ) 



(Xj.Yj) 



A CLOSED PATH or ROUND TRIP is any path which begins 
and ends at the same node in either of two fashions: 



(1): l 

(2): i 



~1 



v — >-u 
x — -y 



— i 



Since these paths may be redrawn; 
(1): i~ *u^v^ 



(2): i 



-—u 



*-v 



J 



it is clear that a round trip may be made using a different path 
for the return leg from that used for the forward leg. 



THE SPIDER NET AS AN EQUIVALENT STREET NETWORK 

In lieu of representing the actual street network, an equiva- 
lent network was established using essentially the straight line 
paths between area centroids as network links roughly equiva- 
lent to the actual street pattern. Here, then, the nodes are the 
same as zone or sector centroids while the links which join any 
pair of nodes are the paths over which all vehicle trips are pre- 
sumed to travel. This seemingly arbitrary technique can lead to 
reasonable results as discussed hereinafter. By the precedent set 
for this technique in the Detroit Study/ 341 the resultant network 
of linked area centroids has come to be called a "spider-net." 
One-way streets and similar unidirectional asymmetries have been 
introduced by suitable handling of the node neighbors. 

NETWORK REPRESENTATION OF EXPRESSWAYS AND 
RAMP FACILITIES 

The existing and proposed expressway network for the Met- 
ropolitan Area was represented by a similar set of nodes and 
links, representing each and every ramp facility and expressway 
intersection. Unidirectional movements, as in expressway main 
lines, and bilateral asymmetry, such as in the case of expressway 
ramps, are secured through the device of the node-plus-neighbors 
technique. The details of this procedure are indicated in a sub- 
sequent paragraph. 

CALCULATION OF LINK DISTANCE AND TRAVEL TIME 

As indicated above, each link distance is computed directly 
from the coordinates of the terminal nodes of that link. The travel 
time for each link was computed using speeds which were as- 
signed following procedures discussed later. Since the links are 
themselves unidirectional it was possible to have route speeds 
which were significantly different in the two directions of travel. 
Once a travel time is determined for each link, it is possible to 
conduct a search for the minimum-time path between any origin 
and any destination in the network. 

BUILDING THE MINIMUM-TIME-PATH TREES 

The crucial element required both for the distribution of gen- 



erated traffic and also for the assignment of the resultant trip 
transfers to present and projected expressway facilities is the de- 
termination of the set of mini mum-time- path trees radiating from 
each of the more than two hundred fifty volume-producing nodes 
assigned to the Boston Metropolitan Area. 

The logical steps involved in mechanically determining these 
paths and in building the resultant trees have been published by 
a number of writers.' 1 ' 34 ' 36 ' 481 These procedures were modified and 
mechanized as required for incorporation into the computer pro- 
grams prepared for this Study. As finally programmed, the ex- 
pressway network together with its access and egress ramps, was 
appended by stages to the spider-net equivalent street network. 
At each such stage a revised set of trees was obtained, reflecting 
the reduction in time for average movements associated with the 
improved facilities. 

THE ESTABLISHMENT OF A GRAVITY MODEL 

INTRODUCTION 

As previously noted, it was decided to employ the simplest 
possible model which would yield reliable present and future data 
on traffic movements. This model was then calibrated as reported 
later against the O. & D. survey data of 1945 and against screen- 
line counts of 1955 and 1959. 

The logic underlying the use and establishment of this model 
is discussed below. It is perhaps important to point out that all 
generation, attraction, and distribution of trips is based upon the 
assumption of round trips made within the average twenty-four- 
hour day. That is, it is expected that a trip generated at a given 
node on the average day will return to that node within that same 
day. It is evident that this behavior holds for all but a negligible 
fraction of home-to-work trips, and it is true for the majority of 
commercial trips within the area, although of course not true for 
the itinerant salesman or similar trip. Thus a trip may be gen- 
erated in a zone, distributed to its attracting zone, and then re- 
applied from this attracting zone back to its generating zone, 
without the necessity of again being generated at this zone of 
attraction. 



INNER BELT AND EXPRESSWAY SYSTEM 




I 11-1 1 



THE GENERATION OF TRIPS 

The model assumes that the generation potential, G\, for any 
area, can be assumed to be a two-term quantity of the form: 

G i= k (CiPj + dRj) 

where k = generation constant, 

Cj = car ownership, 

Pi = area population, 

d = scaling constant, 
and Rj = modifying statistic. 

The basis for the generation model lies in the fact that the 
great majority of automobile trips are home-based trips for which 
the area population and vehicle ownership statistics are the prin- 
cipal factors producing traffic in a given area. The choice of a 
simple product for the combining law is based on certain results 
from the Washington and Baltimore studies which clearly indicate 
that areas of equal population produce automobile trips in direct 
proportion to car ownership. (59,74) Thus if either the population be- 
comes small or the car ownership is low, the volume of trips gen- 
erated will be accordingly small. 

However, there exist obvious non-conforming patterns which 
are ordinarily handled by other components, purposes, or modes. 
Here these are all included in the "dRi" correction. Ideally this 
modifying socio-economic factor, Ri, would be a statistic such that 
the deviational correlation: 



r = 



EAiRi 



VEA2-ER2 



reaches a maximum, where the deviation, &\, is the computed 
difference between the observed or surveyed trip generation and 
that predicted using kcrPi, alone. This deviation would take the 
form: 

i = ~ v^i) observed " ' (KCj r j ) C omputed 

Actually, several statistics were tried for Ri, including em- 
ployment, population density, and employment density. The final 
model used employment density for Ri, as explained later. 



THE ATTRACTION OF TRIPS 

The attraction potential, Qj, was similarly assumed to be a 
two-component quantity, of the form: 

Qj = Ej + bFj 

where Ej = total area employment, 

b = scaling constant, 
and Fj = modifying statistic. 

Ideally, Fi should be a quantity as nearly independent as 
possible from Ei, yet one which correlates as closely as possible 
with the residual attraction errors using Ei alone. This is directly 
analogous to the situation between aPi and R* in the case of gen- 
erated traffic, as discussed above. The final model used settled 
on the use of retail employment density for Fj, as later outlined. 

THE DISTRIBUTION OF TRIPS 

The actual round trip movements between an area of gen- 
eration and an area of attraction will, of course, depend upon 
the travel time-and-distance between the two areas. It is reason- 
able to assume that a measure of this separation effect will be 
the minimum-time-path determined from the tree-building program 
described above. 

As previously indicated, most currently-used gravity models 
assume that this time-distance effect enters as an inverse power 
law, such that the attracted round trips, Gm # between "i" and "j" 
would be expressed by the formula: 



K 



DS 



wh 



ere 



K 
Dij 



and 



gravitational constant, 
generation potential, 
attraction potential, 
time-distance, 
constant exponent. 



Voorhees and others have noted that significantly better cor- 
relation is achieved when Dij is raised to a variable exponent, 



and includes a suitable terminal time for both ends of the trip, 
rather than using the route travel time, alone. 1761 

Significant insight into the separation effect, 1/Di, can be 
obtained by applying the law of intervening opportunities |671 to 
this situation, thus establishing the probable value of "n" on 
rational grounds. Consider the attraction of an area "j" for 
round trips generated within an area "i," when the minimum 
time for automotive travel from "i" to "j" is known or calcu- 
lated to be Dij. Under the Stouffer hypothesis the attraction ratio, 
an, would be calculated from the formula: 



aij = 



Qj 



J dQ 



where the integral is summed over all areas of attraction for which 
Dik — Dii, which is within the isochrone, or time contour, which 
passes through the zone center of area "j." 

First, under a broad class of circumstances, it might be rea- 
sonable to assume that the attraction potential, Qi, is distributed 
fairly uniformly over the metropolitan area. If this were true, then 



and 



dQ = K • D • dD, K = constant 
Dij 



o /dQ= T' D i, 



This results in an inverse-square-law attraction, namely: 



a ij~ 



2-Qj 



K-D 



'j 



On the other hand, particularly for the attraction of trips 
from the Central Business District (CBD), it is generally true that 
the density of attraction potential decreases with increasing dis- 
tance from the CBD. If we then assume: 



then 



dQ = H • dD, H = constant 



jdQ = H-D ij 



111-12 



NNER BELT AND EXPRESSWAY SYSTEM 



e 



£a rx 



and 



a ij~ 



Q; 



H-Djj 



which yields inverse-distance attraction. 

These results demonstrate clearly the difficulties which may 
develop due to use of a gravity model which employs a constant 
value of "n." Therefore, it was decided to assume an arbitrary 
function of distance of the form: 

f(Dij) = Y + 8 Dy + e D?- 

which includes the linear and square laws as very special cases, 
and to carry out a program of parameter fitting for T, 8, and £ 
based primarily on the 1945 O. & D. survey data. This parameter- 
fitting program, discussed in Section 3, ultimately resulted in the 
conclusion that an exponent of two would be adequate for the 
purpose of the present Study. This function is plotted in Exhibit T-3 
in terms of 2t rather than Dm, since the function of time-distance 
used is the travel time, 2t. In Exhibit T-3, the values of 7 = 0, 
3 = 0, and £ = 1 have been substituted in the equation and the 
resulting curve plotted, to represent an exponent of two, or the 
square law. 

Moreover, in order to minimize the task of fitting the model, 
it was decided to arrange the inter-area attraction formula in the 
form of a dimensionless attraction coefficient, Aij, such that when 
summed over all zones of attraction the total coefficient would 
be normalized to unity. That is: 

E Aij -1.0 

Physically, this ensures that all generated round trips are merely 
distributed to all zones of attraction. This useful result is accom- 
plished by defining: 

Qi 



A ij = 



f(Dij) 



I 



k=l 



Qk 



f(Dik) 



where, as stated, the denominator is summed over all areas of 
attraction. 



THE COMPLETED MODEL 

Any round trip transfer of traffic volume from one zone i to 
another zone j may be stated as the product of the generation 









r UNCTI0N FOR TRAVEL TIME 






16 










14 
















<4,i6)y 


t 


12 






f(Zt)»T + 8(ZU+«(Et) 2 

With X =0 

8 =0 

< = 1 

f(Zt) = (Zt) 2 








10 












is 8 


















6 


















4 


















2 



















t 


IQ-O) —* 
















i t 2 3 < 
TRAVEL TIME, St, HOURS 



Exhibit T-3 

of traffic in zone i and the attraction of zone j for zone i, or: 

Tij = GiAy 

Substituting the values derived for these, the complete gravity 
model ready for scaling and parameter fitting thus is: 



T ij = K(c i P i +dR i ) 



Q 



f(Dij) 



I 



k = l 



Q 



f(D ik ) 



in which 
and 



Qj = Ej + bFj 

f(D i3 ) = T + SDij + e D§ 



LOADING THE NETWORK 

ASSIGNMENT OF TRIP TRANSFERS TO SPECIFIC LINKS 

Once the entire set of minimum-time-path trees has been 
established for each volume-producing node or zone of origin, 
i = 1, 2, . . ., N, it is then possible to load the entire trip trans- 
fer matrix, Tij, onto the set of trees. Since, in general, each link 
coincides with more than one tree, the total link loading is ob- 
tained by summing over all trees in which the particular link occurs. 

This procedure may be alternatively conceived in terms of 
the so-called LINK TRANSFER INCIDENCE MATRIX which gives for 
each and every link a listing of all trip transfers and the volume 
of each which would be assigned to that link. Since there are 
over ten thousand links and more than sixty thousand transfers 
in the final 1975 system for the Standard Metropolitan Area, the 
actual printed display of this complete matrix assumes voluminous 
proportions. 

A third alternative loading concept is the TRANSFER LINK IN- 
CIDENCE MATRIX which gives for each trip transfer a listing of 
each and every link to which it would be assigned. For the same 
reasons as above, a recorded print-out of this matrix is also of 
extremely large magnitude. 

The logical simplicity of the results of application of the 
gravity model depend crucially upon the "all-or-none" principle 
of assignment to a single set of minimum time-path trees. Such 
an assignment is referred to throughout this Study as a FREE 
ASSIGNMENT. 

TRAFFIC ASSIGNMENTS AND SIMULATED TRAFFIC FLOW 

From direct observation, validated by measurement and sup- 
ported by logical analysis, it is known that the average speed of 
the vehicle stream upon any highway section depends upon the 
traffic density. As the traffic density, in number of vehicles per 
mile, becomes very small the average speed will approach its 
maximum limit, while with increasing traffic density the speed 



INNER BELT AND EXPRESSWAY SYSTEM 



111-13 



will gradually decrease until at maximum density the vehicle stream 
will reach standstill. Multiplication then gives the result that every 
section has a maximum capacity of traffic volume, in number of 
vehicles per hour, which is reached when the average speed is 
less than the maximum speed, generally about midway between 
standstill and maximum speed. 

The implication for the present problem is simply that if it 
were desired to simulate traffic flow, the minimum-time-path trees 
for any network would necessarily depend upon the network load- 
ing. But the loading, in turn, depends upon trip desires, which 
in their turn depend upon the minimum travel times. This in turn 
implies that a rational and logical simulated-flow assignment pro- 
cedure, which attempted to predict operational use of the entire 
system as opposed to assignments for planning and design pur- 
poses, would involve a computing program vastly more compli- 
cated than that employed here, which in fact as it stands taxes 
the storage of a large-scale computer such as an IBM 704 or 7090 
to the limit. 

Any rational program for simulated-flow assignment volumes 
would have to provide for the following rational observations: 

a. The inter-area transfers are distributed over a set of 
alternative paths in probable inverse proportion to a 
weighted time-distance. 

b. The travel time of any link and therefore of any path 
which includes the link will depend upon the total volume 
on the link. 

c. The distribution of generated trips will depend upon the 
relative separation of every attraction area in terms of 
travel time. 

A program of this complexity cannot be undertaken by any 
presently available computing machine except on an iterative basis, 
in which the machine is programmed to operate in an extensive 
sequence of converging cycles of iteration. Although such a pro- 
gram has been very recently carried out by others for a city 
represented by a relatively small net, current computer technology 
does not lend itself to such computation for the magnitude of the 
net used in the present Study. 

For the present purposes, then, it is intended to carry out 



all planning and design on free assignment and capacity-restricted 
assignment bases, as opposed to a simulated-flow basis, since all 
design changes can be investigated on the basis of their tendencies 
to increase or decrease computed link loadings. These matters 
are further discussed in Section 4. 

CAPACITY-RESTRICTED ASSIGNMENT 

In order to determine information on a capacity-restricted 
basis, a program was developed which in essence uses the data 
resulting from the free assignment program as a point of depar- 
ture. This is the Time-Saving Rank-Order method, hereinafter re- 
ferred to as the "TISRO" method. The title of this method refers 
to the fact that by definition under free assignment each trip which 
uses the expressway system saves times by so doing, rather than 
by using the street system alone. These trips are listed, or ranked, 
in order of this time-saving, to be used under this method. The 
application is explained below: 

a. There has previously been assigned to the network a set 
of trip transfer volumes generally in excess of capacity, 
on the basis of free assignment. 

b. There are made available in the computer system lists 
of the trip-transfer travel-time from any traffic generat- 
ing point to any other point, via the streets alone and 
via the expressway-plus-streets in cases where such traf- 
fic is alternately assigned to expressways. 

c. For each group of trips, or trip transfer, from origin to 
destination, the travel time via the expressway-plus-streets 
is subtracted from the travel time via the streets alone; 
the remainder is the time-saving accomplished by using 
expressways for some portion of the trip. 

d. These time-savings are then placed in a "positive-saving" 
list in order of magnitude, with the greatest time-saving 
at the top of the list, together with their attendant origins, 
destinations, and volumes. Transfers having a difference 
of zero are placed in a second, or "zero-saving" list. 

e. Each segment of the expressway system, excluding ramps, 
is given a number representing the design capacity, above 
which traffic volumes must not be assigned on that seg- 
ment. 



f. Trip transfer volumes are then assigned to the network 
in order of their appearance on the list of time-savings 
just previously prepared. It is evident that those trans- 
fers having the greatest time-saving would be assigned 
first. 
g. As each transfer which uses a segment of the express- 
way is assigned to each link it uses, the total volume as- 
signed to that link up to that point is compared with the 
capacity figure previously stipulated for that link. 
h. When the total volume assigned to a link attains the 
capacity figure, all other transfers which would use that 
link beyond capacity and obviously have lesser time- 
savings, are removed from the positive-saving list and 
placed on the zero-saving list. 
i. When the positive-saving list has been exhausted, there 
appears on each expressway link a figure not greater 
than either the capacity figure or the figure which ap- 
peared in the previous free assignment, if it was origi- 
nally less than capacity. All those transfers which have 
been denied use of the expressway appear on the zero- 
saving list, which is printed out in such form as to be 
applicable to the design, and these transfers are also 
assigned to the street network, thus providing additional 
valuable information for determination of the necessity 
for street improvement or additional facilities, or both. 
The development of the model system theory was thus ac- 
complished. At this stage of development it stands as a valuable 
extension of prior knowledge to an engineering procedure of ex- 
treme utility in traffic analysis such as was necessary for this Study, 
as well as for further work by others in keeping the results current 
and for additional applications. Considerable work has been done 
by others in the field of such model theory since the initiation of 
this Study; this work continues, however, to be of a research nature 
for urban planning study purposes. The present model is the result 
of a direct application of such theory to engineering location and 
design consideration for an expressway system in a large metro- 
politan area. The implementation and application of the model 
theory here developed is discussed extensively in the following 
Section. 



111-14 



NNER BELT AND EXPRESSWAY SYSTEM 



SECTION 3 - APPLICATION OF THE PRESENT MODEL 



P U B 



Lr c 



RA 



REPRESENTATION OF THE PROBLEM 

INTRODUCTION 

As stated previously, it was recognized in an early stage of 
the development of the mathematical model theory that the facili- 
ties of a high-speed electronic computer would be required to 
accomplish this complex task of determining design traffic volumes 
for the expressways. The theory of single-purpose mathematical 
model generation and assignment having been formulated and de- 
veloped, it remained to implement the theory by selecting adequate 
parameters to represent the modifying terms of the model, pre- 
paring input data for computation, and preparing programs for the 
computer. The input data preparation consists essentially of: 

a. Representation of the roadway systems in spider-net form. 

b. Selection of representative speeds for the roadways. 

c. Preparation of sociological input data. 

REPRESENTATION OF THE ROADWAY SYSTEMS 

THE SPIDER NETWORK FOR STREETS 

A preliminary and essential step in the process of computing 
traffic assignments is the preparation of a synthetic highway system. 
This synthetic highway system, or spider network, was prepared 
based on the assumption that all travel is between or through the 
centroid nodes of the zones and sectors within the Traffic Study 
Area, shown on Exhibit T-4. Refinements were made in the spider 
network consisting of additional node points; an explanation of 
these various types of nodes comprising the base spider network 

follows: 

Traffic Generating Zonal and Sector Nodes. 
These node points have two functions: 

a. To represent sources of traffic generation and points of 
attraction for the gravity model program, and 

b. To represent intersections of traffic flow in the street sys- 
tem. 



Exhibit T-4 
CITY AND TOWN LOCATION MAP 




LEGEND 

STANDARD METROPOLITAN AREA LIMIT 
1945 STUDY AREA LIMIT 
CIT1 OR TOWN LINE 



3000 o sooo 10,000 i>,ooo zroooi't 



MAP SCALE 



INNER BELT AND EXPRESSWAY SYSTEM 



111-15 



DOWNTOWN BOSTON INSET 




MAP SCALE 



Non-Traffic-Generating Sector Nodes 

The zones in some areas were divided into sectors to ap- 
proximate more closely the existing complex street system; these 
sector nodes transmit traffic flow but are not used as traffic gen- 
erators or extractors. 

Bottleneck Nodes 

Certain physical barriers, such as the Mystic and Charles 
Rivers, for example, preclude certain zone-to-zone movements 
other than at particular locations, such as bridges. All traffic 
flow between such zones must of necessity use these crossings, and 
bottleneck nodes have been introduced at these locations to rep- 
resent such barrier crossing-points, thereby requiring traffic to 
funnel through these points to cross the barrier. 



Exhibit T-5 
ZONE AND STATION LOCATION MAP 



LA3I 



) \ 

/ 40 8 23 i ) \ 



"V\ 4 



131 



161 




4 1022 \/ — / \ 

V"\ An 

\ c_ 4,, e jX.ja 



4 3 12 5 



j ' \ -t— . 4 112 6 {*—- 




\ _ / 4 372 8 

V n^PTl #^W >so3o-:^yj?^\M< 3a ** 

\ .m-K 230 ^ ! sfir m \ \ \ tooso^. > Ja«^ A 

m _^''< / i^^y yaw n/n 

\ 4 02* W/ |—r- i wow' ' ) \ 



J 




r- ""* 15010 

"N 1 --._ "^s^Y-^T / \ 03Z ' 

X I ,' ~~~~~r \ " y I 0323* \ 

V . / 0337* ', / / 01J<#V"~-4--'T 

//' 3 6660 




A. I V ftSJJ* 



0336*,^^ I \ 

0*0/0 K / ^.!o33ai 

■ \ y' 0340#i 







LEGEND 

^M^M STANDARD METROPOLITAN AREA LIMIT 
1943 STUDY AREA LIMIT 

CITY OR TOWN LINE 

20NE LINE 

19060 ZONE NUMBER 

@ 1945 STUDY AREA EXTERNAL STATION 

A STANDARD METROPOLITAN AREA 

3QI EXTERNAL STATION 

1906* ZONE NUMBER WITH SECTOR SUBDIVISION 

IK- REPLACES SECTOR IDENTIFICATION 

o&rj 



3 000 S0 OO IQ.OtlO lS.000 !0,o oori 
MAP SCALE 



111-16 



INNER BELT AND EXPRESSWAY SYSTEM 



A. 








'©c 



I \. 



• NORTHERN 

• EXPRESSWAY 



°Oo< 



H» o°°oo 

°°°o °° 


NORTHWEST O 
EXPRESSWAY °q 

°o 



NORTHEAST • 
EXPRESSWAY • 



// v . 

tP • INNER \ _• 

# • BELT •• > 



.-••• MASSACHUSETTS TURNPIKE EXTENSION ^ # « « Al 

..© \ \W>'> 

# «* MASSACHUSETTS • 2t^^ *• 

fc « TURNPIKE ••. *Z • ' 

/: • 

/ ? : 



SOUTHWEST 
EXPRESSWAY 



:/ 





LEGEND 

STANDARD METROPOLITAN AREA LIMIT 



• ••• EXISTING EXPRESSWAYS, ALL NETS 
OOOO PROPOSED EXPRESSWAYS, ALL NETS 

• •## PROPOSED EXPRESS WA YS, NETS 1,3 
—m% PROPOSED EXPRESSWAYS.NET 2 
GS00 PROPOSED EXPRESSWAY, NET 3 



Station Nodes 

The external station nodes, representing the study area limits, 
serve as transmitting points for all trips from or to the study area. 
There are two such sets of station nodes, the first to represent the 
1945 study area limits, and the second to represent the 1950 
Standard Metropolitan Area limits, which comprise the limits of the 
Study Area. In the expressway assignments, the first set was re- 
tained in the spider network as route nodes. 

Route Nodes 

After the previous nodes were geographically located, an 
overlay plan of the existing arterial street system was prepared, 
and wherever these travel paths deviated significantly from those 
described by the original network, "Route Nodes" were introduced 
to represent such arterials as a further supplement to the spider 
network. 

Dummy Nodes 

In order to comply with efficient computer memory storage 
capacity, a node could be linked to a maximum of seven node 
neighbors. Whenever conditions created more than seven neigh- 
bors, a dummy node with the same location coordinates was intro- 
duced, thereby increasing the neighbor capacity of a node to 
twelve. 

The initial coding began with the reduction of cities and towns 
shown in Exhibit T-4 into the zones of the 1945 Study Area, as 
shown in Exhibit T-5. The centroids of these areas were geograph- 
ically located with respect to their centers of population and the 
Massachusetts grid coordinate system. 

The various types of node described above were then con- 
nected by links in such a way as to produce a skeletonized pattern 
of travel paths in the basic 1945 Study Area spider network. Thus 
a given link of the spider network was so planned as to represent 
the equivalent of a combination of streets whereon vehicles could 
travel between one center of generation or attraction and another. 



Exhibit T-6 
EXPRESSWAY NETS CODED FOR ELECTRONIC COMPUTATION 



INNER BELT AND EXPRESSWAY SYSTEM 



111-17 



For the design year 1975, the area coded into the street net was 
expanded to the limits of the Study Area. 

THE EXPRESSWAY NETWORKS 

The networks representing the existing and proposed ex- 
pressways for the various years were prepared on the "overlay" 
principle using the basic spider network of 1945 as a datum. The 
links of these networks, unlike the street net, were prepared in one- 
to-one correspondence with the physical sections of the expressway 
so that it would be possible to determine the ramp volumes, as well 
as the mainline volumes as developed by the model generation and 
assignment program. A special code was devised so that a five- 
digit node identification number indicates the expressway serial 
number, the interchange number, the traffic direction on the ex- 
pressway and whether the node is on the expressway or at the 
street-end of a ramp. 

Existing Expressways 

The work of coding the existing expressways followed the 
same procedure as that for the basic spider network. The express- 
ways existing in 1955 were prepared as an addition to the basic 
1945 net, and the resulting net was then used for computations 
referring to 1955. Representation of the expressway construction 
which took place between 1955 and 1959 was then added to this 
network in the same manner to yield a net for computations re- 
ferring to 1959. The existing expressways, as shown in Exhibit 
T-6, consist of the Northeast Expressway to the Revere Airport 
Interchange, the East Boston Expressway to McClellan Highway, 
the Central Artery and its extension to Massachusetts Avenue, the 
Southeast Expressway to Hingham, the Fall River Expressway, the 
Massachusetts Turnpike from Route 128 westward, Route 3 from 
Route 128 to the northwest, the Northern Expressway, and Route 
128. 

Proposed Expressways 

In like manner the proposed expressways were prepared for 
computer input; a total of three different network configurations 
were coded and used in computer traffic assignments. Common to 
all three, as shown in Exhibit T-6, are the proposed Route 1-95 in 



the northeast quadrant with its connectors to the Northeast Express- 
way, to the East Boston Expressway, and to Beverly and Salem; 
Route 1-95 in the southwest quadrant south of Route 128, and the 
Southwest Expressway northward to Neponset Valley Parkway; the 
Massachusetts Turnpike Extension (Western Expressway) between 
the Inner Belt and the Boston-Newton line; the Northwest Express- 
way from the Inner Belt to Route 2 and its connection with the ex- 
isting Northern Expressway; the extension of the Northern Express- 
way to the Inner Belt; and Route 2 from the Northwest Expressway 
to the west. 

For the expressways which are the subject of this Study, it 
was recognized that most of the alternative locations which were 
studied would provide essentially similar traffic service to the areas 
through which they pass. Therefore, those alternatives which rep- 
resent the greatest variations in alignment were chosen for inclusion 
in the computer-assignment networks so that assignable volumes 
would be available from one or another of the computer outputs, 
or from interpolations between outputs, for any of the alignments. 

Network One thus included additionally the Inner Belt along 
the "Ruggles Street route" in Boston and the "Brookline Street 
route" in Cambridge; the Southwest Expressway from the Inner 
Belt to Neponset Valley Parkway by a westerly route; the Western 
Expressway from Route 128 to the Boston-Newton line by the 
"railroad route"; and Route 3 from Route 128 to an interchange 
with Route 2 at the Arlington-Lexington line. 

Network Two included, in addition to those expressways com- 
mon to all nets, the Inner Belt along the "Tremont Street route" 
in Boston and the "River Street route" in Cambridge; the Southwest 
Expressway from the Inner Belt to Neponset Valley Parkway by an 
easterly route; the Western Expressway from Route 1 28 to the 
Boston-Newton line by the "river route"; and Route 3 from Route 
128 to an interchange with Alewife Brook Parkway. 

Network Three included the Massachusetts Turnpike Extension 
in its entirety from Route 1 28 to the Central Artery in the vicinity of 
South Station; in all other respects this network was identical with 
Network One. 



SELECTION OF REPRESENTATIVE SPEEDS 

LINK SPEEDS 

The generation and assignment program evaluates the travel 
time between each of the connected nodes of the spider network 
representing the road system of the Boston Metropolitan Area. This 
evaluation is based upon the computed straight-line link distances 
and upon a speed code number assigned to each link. The speed 
code consists of one of the digits 1 through 9, each of which repre- 
sents a speed in miles per hour, in five-mile-per-hour increments. 
The first step in the process of assigning a speed code number to a 
link was to compare the link geographically with the street or streets 
which it represents, and to take into account the difference in travel 
distance between the link and the streets. The speeds were then 
based upon total elapsed time from point to point including normal 
delays and stops. 

In assigning speeds, reference was made to the following 
sources of field test data: 

a. Travel time studies on Boston streets, arterial highways, 
and Route 128 made by the Joint Highway Research 
Project of M.I.T. and the Massachusetts Department of 
Public Works. 01 ' 12 ' The data for these studies was col- 
lected by the floating-car method and stopwatch-timed 
observations. The study was conducted on selected major 
streets of downtown Boston and outlying areas. 

b. M.I.T. Bachelor of Science theses on highway travel con- 
ditions and travel times between 1948 and 1958. (3I "' 42) 

c. Speed studies made for the Metropolitan District Com- 
mission on M.D.C. parkways and connecting arterial streets 
by their consultants, Bruce Campbell & Associates of 
Boston. The data for these studies was collected by two 
methods. In one study speed-delay data was obtained by 
use of an instrumented floating car, while in another a 
radar speed meter was used to determine 85-percentile 
speeds at selected locations. 

d. Current speed runs on arterial highways by the consul- 
tant's staff, used to verify the continuing applicability of 
the above-cited references. Average running time obser- 
vations were made over a period of weeks on selected 



111-18 



INNER BELT AND EXPRESSWAY SYSTEM 



'A/ 
IC 



major arterial and expressway routes. 

The speeds used for the spider nets represent considered judg- 
ment on average daily speed in both directions consistent with 
known average daily traffic (ADD. Speeds were first assigned to 
the spider network representing the street pattern in 1945 without 
expressways. In assigning speeds a critical point-to-point exami- 
nation was first made of the spider network with reference to the 
actual conditions of the highway system. Speeds were then as- 
signed to the links according to the speed characteristics of the 
actual highways represented. Since the spider network links used 
in the computations are straight between points and the road net 
usually is not, allowance was made to take this difference into 
account, using the above-cited references and the Detroit Study 
airline-road distance curves' 55 ' as guides. The speeds between pairs 
of points not representing an arterial highway were obtained by 
examining the map to find a practical route and the characteristics 
thereof between these points. The speed was then assigned accord- 
ing to the characteristics of this route. 

In the determination, speeds were rounded off to 5 miles per 
hour (mph) increments. In general, the street network speeds as- 
signed were 10 mph in the Central Business District, 15 mph in the 
outer fringe of this district, 20 mph in the inner suburbs, and 25 
mph or over in the outer suburbs, depending upon local conditions 
and type of road. 

These speeds were then revised as necessary to the years 
1955 and 1959, for use with the 1955 and 1959 spider nets, and 
speeds for the expressways existing in these years were added. 
Speeds were then determined for the expressway nets for 1 975, and 
the street speeds based on 1959 conditions were applied to the 
1975 network without change. Although it is possible that the 
building of the expressway system will cause an increase in speed 
on some streets due to reduction in traffic volume, experience has 
shown that such benefits are usually temporary and tend to dis- 
appear as local traffic builds up. 

Speeds were applied to the 1975 expressway nets giving con- 
sideration to actual speeds on sections completed as of 1959, and 
on other existing expressways similar in design to proposed sec- 
tions. The expressway speeds adopted were 30 mph on the Inner 



Belt, 40 mph on radials for the first four miles out from the Inner 
Belt, and 50 mph for sections beyond four miles. Ramp speeds 
were set at between 15 and 25 mph. 

The speeds assigned to the Mystic River Bridge and Sumner 
Tunnel, both toll facilities, were first assigned on the above-noted 
bases, and subsequently reduced to reflect the well-known dim- 
inution in desire to use such facilities due to the existence of tolls. 





FUNCTION FOR TERMINAL TIME 

0.18 




10 




















(250,0.166) 


50 


9 

8_ 

7_ 
k 

II, 

1 

4 

3_ 
2_ 

1 


0.16 






















0.14 




tT — »(*) 

With a =0.017 hours, 

=0.6XI0~ 6 hrs.-sq.mi./empl., 

t T =O.OI7+0.6X10- 8 (^) 












0.12 














O.IO 






















I 

0.08 






















0.06 






















0.04 






















0.0 2 
























(0,0.016 


61 





















0.00 


25 50 75 100 125 150 175 200 225 2 
RETAIL EMPLOYMENT DENSITY, E s /S, THOUSANDS / SO. Ml. 



Exhibit T-7 

TERMINAL TIME 

The various possible methods of introducing terminal time 
per trip were investigated. Terminal time is defined as the amount 
of time required for a vehicle to get on the road at the start of 
a trip, and to find a place to park at the end of the trip. On the 
basis of these investigations terminal times were added to the 
previously computed sum of link-times to arrive at a total travel 
time: 



where 



and 



2t = 

t Ti = 

t T j = 



total travel time, 

sum of link-times for path, or path-time, 
terminal time for origin (Zone i), 
terminal time for destination (Zone j). 



On a rational basis terminal time can be expected to vary directly 
with retail employment density with acceptable correlation. For the 
suburbs, with a low retail employment density, the terminal time 
might rationally be of the order of magnitude of one minute, while 
in the most heavily commercialized zone of downtown Boston, with 
a density of roughly 250,000 retail employees per square mile, 
terminal time might conceivably be of the order of magnitude of 
ten minutes. These boundary conditions were used to establish 
a linear variation in terminal time of the form: 



t T = a -f & 



E S 



where 



and 



t T 

E s 
S 



terminal time in zone specified, 
fitting parameters, 
retail employment, 
zone area, square miles. 



The Greek-letter values may then be varied to establish the 
validity of the relationship and to aid in arriving at a best fit 
of computed to surveyed volumes. In Exhibit T-7 the values a = 1 
minute in a residential zone (no employees) and P = 0.000006, to 
yield 10 minutes at 250,000 retail employees per square mile, 
have been substituted in the above equation and the resulting 
function plotted. These values were determined by the subse- 
quent use of computer parameter-set runs to yield adequate results 
and were therefore used in applications of the gravity model 
equation. 

SOCIOLOGICAL INPUT DATA 

GRAVITY MODEL INPUT REQUIREMENTS 

In the gravity model theoretical study, the population factor 
was hypothesized as the major multiplier of car ownership; a modi- 
fying multiplier having low correlation with population was also 



INNER BELT AND EXPRESSWAY SYSTEM 



1 1 1- 1 9 



specified as a term of the generation section of the gravity model 
equation. Similarly, in the attraction section of the equation total 
employment was propounded as the major factor, to be modified 
by some other non-correlating factor. The nature of the car-owner- 
ship factor to be used, as well as the types of modifiers, were 
then determined. 

Simultaneously with the preparation of network input data, 
the relationship between the various available types of sociological 
data were therefore studied. These studies were conducted by 
plotting, on a town-total basis, one factor against another and 
visually noting the amount of correlation or lack thereof. These 
plots included: 

a. Vehicle registration vs. population. 

b. Vehicle registration vs. dwelling units. 

c. Vehicles per dwelling unit vs. labor force. 

d. Population vs. labor force. 

e. Population density per square mile vs. labor force, 
f. Population density per square mile vs. dwelling units. 

g. Population density per square mile vs. vehicle density 

per square mile, 
h. Total employment vs. labor force, 
i. Total employment vs. retail employment, 
j. Total employment vs. retail employment density per square 
mile. 

These plots led to the following visual observations: 

a. A very high correlation exists between population and 
labor force per town. 

b. A low correlation appears to exist between population 
density and labor force. 

c. A low correlation exists between total employment and 
retail employment. 

d. A low correlation exists between vehicles per dwelling 
unit and labor force. 

On the basis of these observations, it was postulated first 
that figures for vehicles per dwelling unit would serve as a measure 
of car ownership. Second, it was found to be unnecessary to 
deal with both population and labor force, due to the high cor- 
relation between them; the population factor was therefore chosen 



as being a more general statistic than labor force. Third, popu- 
lation density should be used as the modifying term of the genera- 
tion section of the equation, inasmuch as this statistic would re- 
flect the home-based non-work trips. Fourth, retail employment 
density should be used as the modifying term of the attraction 
section of the equation, as representing attraction of home-based 
shopping and commercial trips. These choices were introduced 
into the gravity model equation, and sociological data were com- 
piled for computer input on these bases. 

With the introduction of the modifying factors, the gravity 
model became: 



Tij = K 



Ui ^ + A -s ; 



tint) 




v/ E s j 



Ej + B , ; 
f (Et) 



where Tjj = trip transfer volume generated at zone i and 

attracted to zone j, 
Vj = vehicle registration of zone i, 
Ui = dwelling units of zone i, 
Pi = population of zone i, 
Sj = land area of zone i, 
Ej = total employment of zone j, 
E Sj = retail employment of zone j, 
Sj = land area of zone j, 
K,A,B = fitting parameters, 
f(2t) = function of total path time 

= 7 + 8 (St) +*(£t) 2 
and « = tjj + t T i + t T j 

In order to apply social and economic data, historic or fore- 
cast, to the gravity model, the data had to be made to correspond 
to the 261 traffic-generating nodes of the model. The zones to 
be represented by nodes must necessarily be small so that they 



can be represented by a single point. It can be stated that as 
the basic zone upon which the traffic forecasts are based be- 
comes larger, greater traffic distortions are introduced through 
its representation as a single point. However, in any sociological 
forecast such as population or employment, it is generally agreed 
that greater overall accuracy can be obtained at a large scale 
such as for a metropolitan area, than at a smaller scale such as for 
an individual town within a metropolitan area. Nevertheless such 
a breakdown is necessary in order to meet the input require- 
ments of the mathematical model. In order to do this on a rational 
basis, reasonable criteria were developed as discussed below. 

EMPLOYMENT 

As discussed above, the total employment in a given zone 

was used as one of the indices of the attractive power which 

that zone would exert on trips originating in neighboring (or the 
same) zones. 

Primary Sources. 

Both the Massachusetts Division of Employment Security and 
the U. S. Department of Labor keep records of employment by 
towns in Massachusetts. In neither case do these statistics cover 
everyone employed in the State. The employees not included 
generally fall into the categories of governmental, institutional, 
educational, railroad, charitable and professional groups. Thus 
for any given year, a so-called "covered" employment figure 
can be obtained by towns in the Standard Metropolitan Area. 
Less complete information is available on the remaining, or "non- 
covered," employment. The Division of Employment Security does 
make an estimate of total employment for a group of 41 towns 
in the Boston Metropolitan Area. While this estimate includes all 
persons employed, it is not on an individual town basis. Thus it 
was necessary to supplement the covered employment for each town 
with known concentrations of non-covered employment such as 
the Boston Naval Ship Yard, Massachusetts General Hospital, 
Harvard University and other institutions. In addition, some por- 
tion of the difference between total estimated employment and 
covered or known employment had to be added to each town's 
employment figure. 



111-20 



NNER BELT AND EXPRESSWAY SYSTEM 






RAP-i 



Distribution of Town Employment Into Zones. 

After estimates of employment by towns for the present and 
past years were completed they were further subdivided to corre- 
spond to the basic origin and destination zones. This breakdown 
of employment was made on the basis of the acres of business 
and industrial land use in the various zones of a town. Within 
any one town, total employment was distributed among the zones 
of that town in the same proportion as the acres devoted to busi- 
ness and industrial uses. 

Distribution: City of Boston. 

The above procedure provided an adequate basis for dis- 
tribution of employment in the towns surrounding Boston, but it 
was clear that this basis should be refined for the City of Boston. 
This is due to the intensity of land development, especially in the 
Central Business District, where the amount of land area devoted 
to business and industrial activities probably does not give a re- 
liable index to the amount of employment, so that a more detailed 
approach was decided upon. Expedited by the Greater Boston 
Economic Study Committee, a report by the Massachusetts Division 
of Employment Security for the City of Boston on employment data 
was obtained. This report gave an activity code number, firm name 
and address, and number of employees of all firms which were 
covered during 1957. From this information, covered employment 
by zones was obtained directly with the aid of a city street atlas. 

There is no reliable land-use inventory map of the Metro- 
politan Area for 1945. The present land use was therefore used 
as a guide to the distribution of 1 945 and 1 955 employment among 
zones. This tended to introduce a degree of insensitivity into com- 
parisons between 1945 and 1957 employment by zones. However, 
important changes in land development would be reflected by the 
covered-employment figure for the town, and the insensitivity would 
apply only to the distribution of this figure among the zones within 
the town. 

Covered employment statistics were available for each year 
through 1958, but were not at the time of analysis available for 
1959; the two-year trend 1955-1957 was therefore extended to 
1959 to obtain the statistical information for that year's input. 



Total Employment, 1975. 

Estimates were made of total 1975 employment in various 
areas of the metropolitan region, as discussed in Part IV of this 
Study, and were then distributed among the individual towns. A 
further distribution of net employment gain or loss for individual 
towns was made among the zones within the towns. This further 
distribution was based on previous data related to available in- 
dustrial and commercial sites, the demand for such development 
in the particular area, existing zoning regulations, and estimated 
redevelopment sites and rates of development. 

Retail Employment. 

Retail employment density was used as the most indicative 
and most readily obtainable index of the magnitude of retail 
commercial activity and, therefore, attraction power for those trips 
whose purpose is shopping. Another possible index considered 
was retail sales. However, this would be subject to certain limita- 
tions as an indication of attraction power due to the varying na- 
ture of the product sold, e.g., a jewelry store versus a stationery 
store. The volume of retail sales has the additional disadvantage 
of being difficult to obtain accurately. 

Retail employment statistics were compiled, in much the same 
manner as were total employment statistics, from the Division of 
Employment Security town-level figures for 1945, 1955 and 1957. 
As in total employment, the 1955-57 trend was projected to obtain 
the 1959 figure. The retail employment total for each town was 
distributed among the various zones within the town in direct pro- 
portion to the land area which is devoted to commercial activities. 

Retail employment for the design year 1975 was established 
by towns, and the net difference, 1959 to 1975, was distributed 
according to the land development treatment as used with total 
employment. 

DWELLING UNITS 
Primary Sources. 

The U. S. Census lists dwelling units in its decennial census 
reports, and these data have been used for reference purposes. 
For the intervening years, the various electric power companies' 



and the New England Telephone and Telegraph Company's yearly 
estimates of the number of households or residential customers 
in their service areas were used. These estimates generally take 
into account new construction, conversions, and demolitions. The 
electric companies are required by law to report annually to the 
Massachusetts Department of Public Utilities the number of resi- 
dential customers which they serve. The number of residential 
customers approximates the number of dwelling units. All of the 
above source material was analyzed in the course of this Study. 
The electric company data was used in general for the municipali- 
ties surrounding Boston. On the other hand, the telephone ex- 
change data gave a better breakdown within the City of Boston, 
but was subject to certain necessary adjustments since the tele- 
phone exchange boundaries do not correspond exactly to the 
origin and destination zones. The exact locations of exchange 
boundaries were obtained so that the comparison of areas could 
be carefully made. 

Distribution Into Zones. 

The municipality totals for dwelling units were distributed 
among the zones in direct proportion to the population per zone. 
Although this procedure disregards any variations of family size 
which may exist within a single town, it was deemed entirely 
adequate for this type of distribution. 

Dwelling Unit Projections, 1975. 

The 1975 projections reflect both the existing inventory of 
dwelling units and the net increase or decrease in population. 
The ratio of population to dwelling units was calculated for each 
of the cities and towns for 1959. This factor was then applied 
to the net increase or decrease in population to determine the net 
increase or decrease in dwelling units. Thus the number of dwell- 
ing units in 1975 is given by: 



DU 75 = DU 59 + 



Pop 



75 



Pop 



59 



(Pop/DU) 



59 



For the twenty-four cities and towns in the 1945 study area, 
the ratio for each town was applied to the population change for 
that town. However, for the forty-one additional towns included 



NNER BELT AND EXPRESSWAY SYSTEM 



111-21 



10.0 






POPULATION TREND 
















80 


9.0 


















80 


















7 


















6.0 


















5.0 


COR 


MON WEALTH 


OF MASSACHL 


SETTS— 7 




___~ 


---— •*" 




4.0 




_ 


















</> 3.0 


















i 

si 

>' 24 


STAN 


bosto 
)ard metrop 

950 CENSUS A 


N 

DLITAN AREA 

3EA LIMIT ) 






--—"-"" 








1.0 


•^***^ SI 


ANDARD METF 
EXCLUD 


(OPOLITAN Af 

NG BOSTON 


EA -7 ~- 










0.9 


















0.8 




CITY OF BO. 


TON-j? 












0.7 










~^^^^ 








0.6 


^ 
















0.5 


















0.4 


















IS 


10 19 


20 IS 


30 19 


40 19 
YEAR 


50 19 


60 19 


70 IS 


75 IS 



Exhibit T-8 

In the Standard Metropolitan Area, the average persons-per- 
dwelling-unit ratio was used throughout, since variations did not 
appear significant. 

POPULATION 

The population movement and expansion within the Boston 
Metropolitan Area, based on the Federal Census Reports of 1910 
through 1960, with projections to 1975, is illustrated in Exhibit 
T-8. Massachusetts census data was not used therein because 
the two census reports, Federal and Commonwealth, are taken 
on different bases; the Federal census includes students and mili- 
tary personnel wherever they are found, while the Massachusetts 
census includes only those regularly rather than temporarily resi- 
dent. The limits of the Standard Metropolitan Area have in the 
past changed with each Federal census, and for this Study the 1 950 
Federal census limit of 65 cities and towns has been used. 

Using the 1940 census year as a base, the percentage 



change over the years is shown in Exhibit T-9 for the Common- 
wealth of Massachusetts, the 1950 Standard Metropolitan Area 
of 65 cities and towns, the Standard Metropolitan Area exclud- 
ing Boston, and the City of Boston. It is apparent that the area 
surrounding the City of Boston has grown at a much higher rate 
than the Commonwealth as a whole. The Standard Metropolitan 



60 
55 

50 

45 

40 

-. 55 

5 20 

I' 5 - 

k. 10 

\ 
% 5 

0_ 

-5 

-10 

-15 

-20 
IS 


POPULATION TREND-PERCENT 














80 


















s 
s 
s 

s 








* 
* 


















**> 

4' 


^ 








r ^i^ 
















W' 






y^^^ 




















N?> 
















































40 1950 I960 1970 1975 19 

YEAR 



Exhibit T-9 

Area excluding Boston has increased by 29.1% from 1940 to 
1960 and for the time period 1940 to 1975 there is an expected 
increase of 51.1 %. The Standard Metropolitan Area with Boston 
included has shown a 15.4% change for the period 1940-1960 
and an expected increase of 30.2% for the period 1940-1975. 
The Commonwealth as a whole increased 19.3% for the years 
1940-1960 and has an expected increase for 1940-1975 of 
33.7%. While the other areas have been increasing, the City 
of Boston has fluctuated with an increase from 1940 to 1950 
of 4.0%, but a decrease from 1950 to 1960 of 13.4%, so that 



the overall change from 1940 to 1960 has been a decrease of 
9.5%/ and the expected change from 1940 to 1975 is a de- 
crease of 7.9%. 

Population estimates for computer input were prepared for 
the years 1945, 1955, 1959, and 1975 for all municipalities, 
and the basic distribution by zones was made for 1955. The 
estimates for the other years, except 1975, were proportioned 
among the zones on the basis of the 1955 population distributions. 
The net increases or decreases in town or city populations be- 
tween 1959 and 1975 were assigned to various zones on the 
basis of available land, accessibility, existing zoning, and prob- 
able redevelopment sites. In some cases a redistribution of popu- 
lation within a city or town was judged probable, so that the net 
increase or decrease, 1959 to 1975, was the result of a popula- 
tion decline in one portion thereof and a population increase in 
another section of the same area. This is especially true in the 
case of Boston where the central city population is already de- 
clining in relation to areas nearer to the periphery of the city. 







VEHICLE REGISTRATION AND TRAVEL 




30 




4.0 


















3.0 












S* 






2.0 


C0MM0I 


WEALTH OF 
EHICLE REG 


(ASSACHUSETTS ^. 


-^"- 






20 


1 

5 10 








** COMMONWEALTH OF 

S MASSACHUSETTS 

/ VEHICLE TRAVEL 


P 1 
Ui 

1° ti 


^ 09 




V>^/ 














i 

5 Q 


%. 08 


















>" 07 
















% 

£ 06 










VEHICLE REGISTRATION 




^ 05 


















S 04 


















-J 

1 

1 


3 0.3 


















G - 

02 


CITY OF BOSTON- 


VEHICLE REGISTRATION^ 




















ESTIMATED 










009 


















08 


















07 


















0.06 




















1930 1940 1950 I960 1970 1975 1980 
YEAR 



Exhibit T- 10 



111-22 



INNER BELT AND EXPRESSWAY SYSTEM 



MOTOR VEHICLE REGISTRATION 

Primary Sources. 

Vehicle registration and travel trends are illustrated in Exhibit 
T-10. The two sources of information relating to motor vehicle 
statistics were the Bureau of Excise Tax of the Commonwealth De- 
partment of Corporations and Taxation, which lists the number of 
motor vehicles and trailers on which the excise tax is levied, and 
the New England Auto List, a private organization which lists yearly 
passenger car and truck registration by towns. The excise tax list- 
ing results in a higher figure because trailers are included with 
motor vehicles, and also because of surrendered plates and re- 
registration duplications. The New England Auto List was used as 
the source of data for the years 1955 through 1958. The 1955- 
1958 trend figures extended to 1959 were also used. Statistics of 
the Bureau of Excise Tax were used for the year 1945. 

Distribution into Zones. 

The total vehicles per municipality were distributed into the 
city or town component zones in proportion to the resident popu- 
lation in those zones. Within the City of Boston, the New England 
Auto List records figures for Brighton, Charlestown, Dorchester, East 
Boston, etc.; within these classifications, total vehicles were distrib- 
uted in direct proportion to the population. 

1975 Motor Vehicle Projections. 

In projecting the motor vehicle registration, both the area 
differences in vehicle ownership and the changing ratio of per- 
sons to vehicles were taken into consideration. The persons-per- 
vehicle ratio for each of the cities or towns was calculated and 
the results were grouped according to geographic location and 
similarity of economic characteristics, of which vehicle ownership 
is one. The overall persons-per-vehicle ratio of each of the groups 
of municipalities was then calculated. The next step was to plot the 
persons-per-vehicle ratio for the original 1945 study area at sev- 
eral points over the last fifteen years in order to determine the rate 
at which vehicle ownership has been increasing with time. Present 
trends were extended to 1975 and compared with trends of other 
metropolitan areas, as illustrated in Exhibit T-l 1. The persons-per- 



vehicle ratio as projected by this method was found to decrease 
between 1959 and 1975 by a factor of 1 .22. 

The 1975 population for each city or town and each zone 
was then related to two factors, the 1959 persons-per-vehicle 
ratio of the particular group of cities and towns to which it be- 
longs, and a constant factor representing the projected average 



PERSONS-PER-VEHICLE RATIOS 



REGION 




TAMPA METROPOLITAN AREA 



1945 



'SO 



'55 



'60 

YEAR 



'65 



'70 



1975 



Exhibit T-l 1 

change in the persons-per-vehicle ratio between 1959 and 1975 
Thus the number of motor vehicles in 1975 is given as: 



MV 



75 



POP75 ( 



1.22 



(Pers/Veh) 5 9 



COMPUTER PROGRAMMING 

The preparation of computer programs was carried on con- 
comitantly with the previously discussed work. As illustrated in 
Exhibit T-l 2, and described below, seven major programs were 
prepared, primarily in IBM FORTRAN language, three of which in- 
cluded optional sub-programs. Also illustrated is the generalized 




procedure of computer operation necessary to yield 
output desired. 



any given 



LINK-DISTANCE AND LINK-TIME PROGRAM 

This program computes, from the spider network input, the 
distance between neighbor nodes, or link-distance, on the basis 
of the coordinates provided, and the travel time between nodes, 
or link-time, on the basis of speed codes provided. 
Ramp Impedance and Toll Delay Sub-Program. 

This program was prepared in order to add to expressway 
ramp link-times one of four assignable constant times in thou- 
sandths of an hour, to represent the effect of street congestion 
on ramp operation. It may also be used to assign additional 
time to links representing toll facilities, given constants for cents 
per minute and cents per mile which are relevant, as follows: 



tT = t T . + L 



D 



where 



and 



t T = total link-time, minutes, 

t L = link-time computed from coordinates, minutes, 
L = link-distance computed from coordinates, miles, 
C D = distance cost of using toll facility, or toll charges, 

in cents per mile, 
C T =time cost of using toll facility, or payment accept- 
able to operator per minute of time saved, in 
cents per minute. 



Although of considerable value in many applications, it was 
ultimately found inadvisable to use this sub-program, since the basis 
for its use was in this case in direct conflict with the concept of 
capacity-restricted assignments as applied to the Massachusetts 
Turnpike. 

MINIMUM PATH TIME (TREE-BUILDING) PROGRAM 

This program computes from the results of the link-time pro- 
gram, the minimum-time path from each volume-producing node 
to all other nodes. It is called "tree-building" because a plot of 
the minimum-time paths from any one node to all other nodes 
has the appearance of a tree. 



INNER BELT AND EXPRESSWAY SYSTEM 



111-23 



BLOCK D I A G R A M 



F 



PROG RAMS 



/s^ Link- Distance S**S 

\ | ond [ 2 

^ Link-Time ^ 



IA 



I 



Minimum Time 

Path 
(Tree Building) 



Romp - Impedance 

and 

Toll Delay 



("2A 



Selected 

Tree 
Output 



3A 







© 


Grovity 

Model 
Molrix Generation 












* 






f~ 


(3B 


4 




* 


(3^ 


* 


Sum Rows 

ond Columns 

(Trip Ends) 


Matrix 
Comparison 
Statistical 

Analysis 


[35 


Volume-vs.-Time 

and 

Volume*V5;0istonce 


and D 

Display 



@ 


Fre e 
Assignment 




d 


TISRO 
Assignment 


<t 


Unk -Transfer 
Incidence 
Matrix 


d 


Transfer- Link 

Incidence 

Matrix 




* 
















4 




<J 








Comparative 
Link- Loading 


[4B 


Link - Lood 

Comparison 

Statistical 

Analysis 





G E N E R A L 



PROCEDURAL FLOW DIAGRAM 



Link Distances and Times 



Minimum- Path Trees 



Trip-Transfer Matrix Generation 



Free Assignment 




111-24 



Exhibit T- 12 



INNER BELT AND EXPRESSWAY SYSTEM 






Selected Tree Output Sub-Program. 

This program prepares a print-out of a single tree, which 
may then be plotted for analytical use. Any number of such trees 
may thus be prepared. 

GRAVITY-MODEL PROGRAM 

This program computes the amount of traffic generated at 
each volume-producing node on the basis of the sociological input 
data, and further computes the distribution of this traffic on the 
basis of this data and the total time between zones, using the 
minimum-time paths of the tree-building program as a base; the 
result is a complete rectangular trip transfer matrix on magnetic 
tape. 

Sum of Rows and Columns (Trip-Ends) Sub-Program. 

This sub-program reports the sum of each row and each 
column of the rectangular matrix prepared as above. The sum 
of a row added to the sum of the corresponding column then 
yields the total of all trip ends in the zone or sector stipulated. 

Matrix Comparison Statistical Analysis Sub-Program. 

This sub-program provides a statistical analysis of computed 
trip transfers as compared with surveyed trip transfers, and is used 
as a guide in determining the variable coefficient parameters of 
the model. Each computed transfer volume is compared with the 
corresponding surveyed transfer volume, and the difference deter- 
mines the frequency range of differences into which that trans- 
fer is put. A threshold of volume of surveyed transfers to be 
compared may be imposed, and the report contains that thres- 
hold, the number of transfers above the threshold, the parameter 
set identification number, the values of the eight parameters for 
that set, the computed value of the correlation coefficient for that 
case, and the number of transfers in each frequency range of dif- 
ferences. 

Volume-vs.-Time and Volume-vs.-Distance Sub-Program. 

This program first sums the distances along each minimum 
path in each tree, and then tabulates from the trip transfer matrix 
the volume traveling a given time, not including terminal times, 
in increments of one-tenth hour, and a given distance in incre- 
ments of two and one-half miles. 



O. & D. Display Sub-Program. 

This program yields a report of the trip transfer matrix 
prepared in the main program, and states the volumes of each 
trip transfer in that matrix. 

FREE ASSIGNMENT PROGRAM 

This program applies the results of the gravity-model pro- 
gram, the traffic movements between nodes, to the minimum-time 
paths (trees) previously obtained, resulting in a listing of all links 
of the network and the traffic volumes thereon. 

Comparative Link-Loading Sub-Program. 

This program prepares a report stating the link-loading of 
each link in the net from each of two different trip transfer matrices. 

Link-Load Comparison Statistical Analysis Sub-Program. 

This program is essentially similar to that used for matrix 
comparison as noted above, except that it compares the volume 
assigned to each link from the computed matrix with that from 
the surveyed matrix. 

TISRO ASSIGNMENT PROGRAM 

This program assigns traffic with greatest time-savings to 
an expressway only up to the designated capacity of that ex- 
pressway. Traffic which desires to use that expressway, but has 
lesser potential time-saving than that which loads the expressway 
to capacity, is then assigned to the quickest alternate street path. 
The program yields five reports as follows: 

Report I: Link Loadings. 

This report states the vehicle volume on each link due to 
transfers which use that link and have a positive time-saving using 
an expressway path, and also states the total volume assigned 
to that link. 

Report 2: Expressway-Excluded Positive Time-Saving Transfers. 

This report lists each positive time-saving transfer, and its 
volume, which is excluded from its expressway path and reas- 
signed to a street path due to a capacity restriction on an ex- 



pressway link and the existence of other transfers having a greater 
time-saving which use that link. 

Report 3: All Positive Time-Saving Transfers vs. Time-Savings. 
This report tabulates the sum of all trip transfer volumes 
having a stated range of potential time-saving via the express- 
way, in range increments of two-hundredths hours. 

Report 4: Expressway-Assigned Transfers vs. Time-Savings. 

This report tabulates in the same form as Report 3 the sum 
of all trip transfer volumes actually assigned to the expressway. 
In each range, the difference between the values shown in Reports 3 
and 4 is thus the volume which has a potential time-saving via 
the expressway, but because of expressway capacity restrictions 
is assigned to the streets. 

Report 5: Expressway-Assigned Positive Time-Saving Transfers. 

This report lists each positive time-saving transfer, and its 

volume, which has a great enough time-saving to be assigned to 

its expressway path within the capacity restrictions on that path. 

TRANSFER-LINK INCIDENCE MATRIX PROGRAM 

This program prepares a report (Report "6") in which the 
links of the minimum-time path used by each trip transfer are 
presented in order of their use in the street path, and also in 
the expressway path, where such exists. 

LINK-TRANSFER INCIDENCE MATRIX PROGRAM 

This program prepares a report (Report "7") in which the 
load on each link of the net is presented in terms of the volume 
from each trip transfer using that link as a result of the TISRO 
assignment. 

CARD-INPUT PREPARATION 

Of extreme importance to the successful processing of the 
model is the accurate representation of the various networks and 
the accurate preparation of the card decks which serve as input 
to the computer. When it is considered that about 435,000 deci- 
mal digits were coded into these decks, and that the mis-coding 



INNER BELT AND EXPRESSWAY SYSTEM 



111-25 



PREPARATION 



F 



COMPUTER CARD-DEC K INPUT 



Street-Alone 
Network D eck 



PROPOSED EXPRESSWAY DECKS- FIRST ALTERNATE NETWORK 



Existing Expressway Network Decks 



C ap a c i ty Restriction Deck 



Network Deck 




* an Nodes 
♦ •Volume-Producing Nodes 



soc iolog i cal 
Data Deck 



f Bose Mop W — 1> 



Sociological 
Data 



Sociological 
Data List 



S 



Sociological 
Cards 



< 



Count 
265*' 



v.Sociologico 
' '■•■■Oech^y 



Socio 
Oota 
Proof 



LEGEND 



o 

v 



SOURCE MAP 



MANUAL PROCESS 



SOURCE 
DOCUMENT 



MANUALLY-OPERATED 



( ) CARD MACHINES 

K: Keypunch 
V- Verifier 



o 
o 



O 



CARO-HANOLERS 
C- Collator 
S Sorter 

AUTOMATIC 

CARD MACHINES 
I fnterpreler 
P- Printer 
R: Reproducer 



IN-PROCESS 
CARD DECK 



COMPLETED 
COMPUTER-INPUT 
CARO OECK 



REPORT 
(PRINT-OUT) 



MAXIMUM ALLOWABLE 
CARD DECK COUNT 



111-26 



Exhibit T- 13 



INNER BELT AND EXPRESSWAY SYSTEM 



& 






of even one of these digits may completely invalidate the results 
of a computer run, it is evident that careful planning to minimize 
the possibility of error, and elaborate checking procedures to 
eliminate any residual error, are well justified. 

The general flow diagram for preparation of card decks 
to be used as input to the computer is presented as Exhibit T-13. 
The zones, sectors, nodes, street-links and speeds are first plotted 
and coded on large-scale mylar reproductions of U. S. Geolog- 
ical Survey maps, from which the node codes, geographic coor- 
dinates, neighbor nodes and link speeds are listed. The lists are 
then key-punched on IBM cards, and key verified and sorted in 
order of entry node to yield a street-net-deck, which is then printed 
out. This print-out is then replotted on an overlay which is compared 
item-for-item with the original for elimination of error. 

In order to preserve the accuracy of data thus prepared, the 
street- net-deck is then reproduced to serve as a basis for incor- 
poration of the additional data required to represent the exist- 
ing expressways. On overlays representing these expressways, 
each junction point of a ramp with a main-line link or street link 
is coded, and two lists are prepared. The first list enumerates 
all cards to be replaced in the reproduced deck with cards con- 
taining additional information; these cards are removed from the 
deck, the previously-verified information is duplicated, and the 
new data is added thereto. The second list enumerates cards 
that are completely new; these cards are key-punched and verified 
as were the original cards. The entire expanded deck is then printed 
out and the additions replotted on overlays for proofing. This 
process is essentially followed for each additional deck required 
as illustrated in the general flow diagram. 



MODEL EVALUATION 

DATA PROCESSING — PARAMETER DETERMINATION 

The major programs having been proved out, and all 1945 
input data having been assembled, work was commenced on the 
computer to arrive at suitable values of the variable coefficient 
parameters of the gravity-model equation. From the 1945 net- 
work input data, link-times were computed, after which the com- 



TABLE T-l 
FITTING PARAMETER SET VALUES 



Parameter 

Set 


K 

0.40 


A 
0.20 


B 


70 


0.10 


90 


0.60 


0.10 


0.10 


102 


0.34 


0.20 


0.10 


109 


0.256 


0.15 


0.10 


110 


0.40 


0.15 


0.10 


111 


0.375 


0.15 


0.10 



0.017 
0.017 
0.017 
0.017 
0.017 
0.017 



plete system of trees was computed for the 1945 network. 

With these link-times and trees completed, the next step 
was to determine proper values of the parameter B, and the 
Greek-letter parameters, which may be described as determining 
the exponent of time, t. This work, since it refers only to the 
attraction portion of the gravity-model equation, was accomplished 
by estimating probable values of these parameters, and distrib- 
uting input volumes transmitted from external stations to all zones 
on the basis of this portion of the equation and these estimates. 
The results were compared statistically with the known distribution 
of the 1945 station-to-zone survey data, and the parameters re- 
vised to bring the computed distribution into closer agreement 
with this known distribution. The function-of-time equation para- 
meters were varied to represent exponents varying from to 3 
in increments of 0.5; it was found that the square represents an 
extremely good value of the t-exponent in this case, and that 
further refinement of the time-parameters would be impractical 
for the purposes of this Study, although interesting from a re- 
search viewpoint. It was also found that the best value of B is 
0.1, i.e., with total employment as the major measure of attrac- 
tion, the best fit to survey data is obtained by using one-tenth 
of retail employment density as, the additive modifier. 

Holding fixed the parameter values thus found, the remain- 
ing parameters were determined by computing trip transfer vol- 
umes using the complete gravity-model equation, and comparing 



J_ 

0.7xl0-« 
OJxlO- 6 
0.7X10" 6 
0.7xl0- 6 
0.7X10- 6 
0.7xl0- 6 



Primary 
Use 



1.0 
1.0 
1.0 
1.0 
1.0 
1.0 



1955 

1959 
1955, 1959 

1945 
1955, 1959 

1975 



Modifying 
Statistic 



Population 
Density 

Population 
Density 

Employment 
Density 

Employment 
Density 

Employment 
Density 

Employment 
Density 



these volumes statistically with the corresponding values of the 
complete 1945 survey trip transfer matrix. Initial values were 
estimated for the parameters K and A, and computations were 
made to arrive at the best-fit values of these parameters. It was 
thus found that parameter set 70, with values of K = 0.4 and 
A = 0.2 yielded a mean very close to zero in the statistical analysis. 
A list of all parameter sets here referred to is found in Table T-L 

The computer input for the 1955 computations having been 
prepared, the link-times for the 1955 spider network were next 
computed, and the trees were assembled. The 1955 volumes trans- 
mitted by external stations to the zones were then distributed us- 
ing the attraction portion of the gravity model equation, and re- 
sulting trip transfers were compared with corresponding values 
of the 1955 survey data. All available 1955 surveyed trip transfer 
values were then compared as a minor check with computed values 
using the complete gravity model equation. As a result of these 
computations, values of K = 0.6 and A = 0.1 (parameter set 90) 
appeared to yield the best fit for 1955 data. 

With the completion of computer input representing 1959 
conditions, the 1959 link-times were computed and the trees as- 
sembled. 

Since parameter sets 70 and 90, described above, showed 
the best fit of computed traffic to surveyed volumes, the 1 955 spider 
network links were loaded with gravity-model generated traffic 
based on set 70, and the 1959 links were loaded based on set 90, 



INNER BELT AND EXPRESSWAY SYSTEM 



111-27 













TABLE 


T-ll 






















SCREEN-LINE 


ANALYSIS 












Screen-Line 


Year 

1955 


Surveyed 
Volume 


Parameter 
Set 


Computed 
Volume 


Per Cent 
Difference 


Parameter 
Set 


Computed 
Volume 


Per Cent 
Difference 


Parameter 
Set 


Computed 
Volume 


Per Cent 
Difference 


Northern 


340,600 


No. 70 


408,764 


+20.0% 


No. 102 


333,987 


- 1.9% 


No. 110 


348,526 


+2.3% 


Northern 


1959 


510,660 


No. 90 


760,274 


+48.8% 


No. 102 


509,319 


- 0.3% 


No. 110 


499,384 


-2.2% 


Neponset River 


1959 


224,975 


No. 90 


322,358 


+43.3% 


No. 102 


221,191 


- 1.7% 


No. 110 


233,617 


+3.8% 


Downtown Cordon 


1959 


656,350 


No. 90 


1,125,126 


+71.4% 


No. 102 


764,950 


+ 16.5% 


No. 110 


710,741 


+8.3% 



for a cross-check comparison with screen-line data, as described 
below. At this time the 1945 surveyed data was loaded on the 
1945 spider network, and also the 1955 surveyed data was loaded 
on the 1955 spider network. The sub-programs to yield trip trans- 
fer volumes and percentage volumes as functions of travel time 
and distance were also run to aid in obtaining better statistical 
fits of surveyed versus computed data. 

The 1955 and 1959 screen-line checks on the basis of para- 
meter sets 70 and 90, respectively, having shown greater than 
desirable percentage differences between surveyed and computed 
volumes (See Table T-ll), the gravity model equation was re- 
examined in the light of the statistical analyses. It was judged 
that insufficient non-home based traffic was being generated by 
the gravity model; the parameter of total employment density 
was therefore substituted for population density as the modifier 
of population in the generation portion of the equation. The modi- 
fier thus reflects non-home based commercial trips rather than 
the home-based non-work trips previously used. The generation 
portion of the gravity-model equation thus became: 

Further statistical analysis yielded a better fit of 1945 computed 
data to 1945 survey data, although the volume-time analysis indi- 
cated a total volume generated that did not correspond with the 
total surveyed volume of trip transfers. Additional parameter sets 
were therefore used to determine values of K which would yield 



total volumes for 1945 and 1955 having better correspondence 
with total surveyed trip transfer volumes. Using parameter set 102, 
the 1955 net was loaded with 1955 computed volumes, and the 
1959 net with 1959 computed volumes, and screen-line checks 
were made. 

The 1975 input data for the computer having been prepared, 
the 1975 link-times were computed and the trees assembled. Us- 
ing parameter set 102, the 1975 spider network was loaded with 
1975 computed volumes, and also with 1959 computed volumes. 

The 1945 spider network was also loaded with both 1945 
surveyed traffic and 1945 traffic computed on the basis of a 
"K" which is a scaled-down equivalent to that used in set 102 
for the years 1955 and 1959, because all growth curves indicate 
a departure from normal rate of growth for the war years, as 
may be noted in Exhibit T-8, and because a given group of socio- 
logical data would not accurately reflect the amount of traffic 
generated under the abnormal conditions of gasoline and tire 
shortages. It was therefore judged that an equivalent K should 
be used for the year 1945, rather than the same K that is used 
for years of "normal" growth. 

Analysis of the loading of the 1945 net with both surveyed 
and computed volumes revealed a point in the machine program 
logic that required improvement. With the indicated revisions com- 
pleted, new parameter sets were used in conjunction with 1945 
surveyed data and computed traffic to determine the new best 
values of K and A. it was found that parameter set 109, with 
K = 0.256 and A = 0.1 5 yielded a higher correlation coefficent 



than had been attained previously, an acceptable position of the 
mean in the statistical analysis, and a total volume 0.14% higher 
than the surveyed volume. The equivalent K was found for 1955 
and 1959 in parameter set 110, and the 1955 and 1959 links 
were loaded on the basis of this set. A check of the screen lines 
revealed that the volumes involved remained for the most part 
somewhat high, so that a minor adjustment was made to the 
value of K in parameter set 111 to reflect an overall decrease 
in volume of about 5% from that which would have resulted us- 
ing set 110. The final gravity-model used for projection of the 
1975 trip transfer matrix thereby became, including the values 
of parameter set 111: 



Tij = 0.375 



Ui 



P; + 0.15 



E 



S; 



E 



E^ + OUO-g: 



£t) 




E 



Ej + 0.10 ,. 



sj 



(Et) 



/ F • 

and Et=t ;j + 10.017+ 0.7x 10 -g^ 



+ 0.017+0.7x10" 



E 



SJ 



with the terms defined as in the original equations. 



111-28 



INNER BELT AND EXPRESSWAY SYSTEM 









TRIP TRANSFER COMPARISON 








1400 








1300 


























1200 












1 
1 

\MOOC 
















^ 1100 












I 
I 
















£ 1000 












\ 

I 
1 
















k. 

p 900 












i 
| 
















H 












1 

! 
















1 






s 






I 
I 
1 




I 


















£ 

* 
























1 ■ 

5 500 






j 






IS 

f 




I 












^ 400 






a 






15 




o 














1 

5 JOO 












i 

i 
















1 

200 


<-500 










i 


























100 










i 
i 
i 














> + soo 























t 
i 






















-5C 


H3 -400 -3t 
GRAVITY MOD 


'0 -^00 -/o 


o c 


+IC 
» TRAN 


*_>£ 
SFERVC 


+3C 
)LUME L 


+4C 
WFERE 


t5C 
NCES 


to 



Exhibit T- 14 



LINK LOAD COMPARISON 

















1 

MOOE 














700 








ki 

<o 600 














1 














% 
















I 










ki 














ti 


i 










£ 




























S 1 




























>t 




























Q 500 




























Q 


























kj 
















i 










K 




























s 




























*/> 




























y> 400 




























* 




































































j* 












5 












1 Q 


15 


s 












S 












^1 


k 


3 












5 joo 














1 














^i 












Q . 


K 


3 












k 












§ : 


% 


<5 












Ri 














e it 


» 










« £00 
















"i 












% 




























5> 




























% 




























too 


















* 






'" 


i 
















1 














I 


\ — - 





-5000 -4000 -3000 -2000 -1000 H000 *2000 +3000 *4000 *5000 
GRAVITY MODEL MINUS SURVEY LINK LOAD VOLUME DIFFERENCES 







TRIP TRANSFERS BY TRIP TRAVEL TIME 






1.5 










1.4 

1.2 

£ 10 

1 

j£ 0.8 

3 

% 

!ii 0.6 

I 

a. 
it 

K 0.4 

0.2 


































5 






























































I 

\ 
i 












LEGEND 
t!"::m I94b SURVEY 

1945 GRAVITY MODEL 

W~~~ 1959 GRAVITY MODEL 
: 1975 GRAVITY MODEL 








i 
































































































1 

i 






























_____ 




























































| 




. 




























1 


--- 


— ™ 




































1 


























! 





l 
























C 


1 1 1 1 1 1 1 1— 

0. 2 0.4 0.6 0.8 1.0 1. 2 1.4 i 
TRAVEL TIME, HOURS 















Exhibit T- 16 














PERCENTAGE OF TOTAL TRIP TRANSFERS BY TRIP TRAVEL TIME 


50 






45 
































5 


40 
































k, 35. 

£ 30 - 

S 25} 
20 

5 

B 
to 

5 


















LEGEND 

"~P? 1945 SURVEY 

1945 GRAVITY MODEL 

1959 GRAVITY MODEL 

1975 GRAVITY MODEL 





























































































































=-_±9 


;n_- u -iZ- 
































---- 


-.=.- 


































---- 


_-_-_. 


____ 
















.0.2 0.4 0.6 0.8 1.0 1.2 14 1 
TRAVEL TIME, HOURS 









TRIP TRANSFERS BY TRIP LENGTH 








1.5 










1.4 


— 
































'0 




































1.2 


















































LEGEND 
S**- 1945 SURVEY 

1945 GRAVITY MODEL 

I 1959 GRAVITY MODEL 

~"~ 1975 GRAVITY MODEL 








» 1.0 


■*-"" 












































































5 
1 


































_ 

& 0.6 


































£ 

1 
































a. 
p* 0.4 


































o.s 



t 






— 




































__"-- 





































____ 























r ___ 






■- 


_-^_: 


— 










.... 


_J 












■j: ' 






j 


■^t«w 




___""" 


r f" — - --- - - - - 

J 5 10 15 20 25 

TRAVEL DISTANCE, MILES 


30 35 4 


















Exhibit T-18 
















PERCENTAGE OF TOTAL TRIP TRANSFERS BY TRIP LENGTH 


50 






45 


? g 


































40 




































^35 


















LEGEND 

W3& 1945 SURVEY 

1945 GRAVITY MODEL 

1959 GRAVITY MODEL 

1975 GRAVITY MODEL 










§30 
25 

$20 






























































— — — 
































1 

1 

Is 
































10 

5 


t 






— 




































T— 


= 




































--- 


n 


.... 

















5 10 15 20 25 30 35 
TRAVEL DISTANCE, MILES 


40 



Exhibit T-l 5 



Exhibit T- 17 



Exhibit T-l 9 



NNER BELT AND EXPRESSWAY SYSTEM 



111-29 



DOWNTOWN BOSTON INSET 




1 500 O 1500 30 00 FT. 

MAP SCALE 



STATISTICAL ANALYSIS OF COMPLETED MODEL 

TRIP TRANSFER COMPARISON 

Each trip transfer volume of the 1945 O. & D. survey was 
compared with the corresponding transfer of the computed 
gravity-model matrix. The frequency distribution of the differences 
between all sets of corresponding transfers was studied and the 
correlation coefficent for the final parameter set was computed 
to be 0.78; the mean of differences between transfer volumes 
stands at —83, and the standard deviation is 219 vehicles. This 
frequency distribution is illustrated in Exhibit T-14. 

LINK-LOAD COMPARISON 

The matrix of trip transfers of the 1945 O. & D. survey was 
assigned to the 1945 spider network and compared on a link-by- 



Exhibit T-20 
1945 SURVEY vs. MODEL TRIP ENDS 




III-30 



INNER BELT AND EXPRESSWAY SYSTEM 







link basis with an identical assignment of the computed matrix. 
The frequency distribution of the differences between the volumes 
assigned to the link from the survey matrix and those from the 
computed matrix was determined and the correlation coefficient 
for the final set was computed to be 0.96; the mean difference 
stands at +249 vehicles, and the standard deviation is 1101 
vehicles. This frequency distribution for the final parameter set 
is illustrated in Exhibit T-15. 

TRAVEL TIME AND DISTANCE COMPARISONS 

Trip transfers of the 1945 O. & D. survey were grouped ac- 
cording to their travel times, as assigned to the 1945 spider net- 
work, in six-minute increments. The same process was applied 
to the 1945 computed trip transfer matrix, and the resulting curves 
compared, both on a volume and percentage basis; these curves 
are shown in Exhibits T-16 and T-17, respectively. The correla- 
tion coefficient for the comparison of the "survey" curve with the 
"computed" curve is 0.98, Also shown in these figures are the 
curves for the 1959 computed traffic and the 1975 forecast traf- 
fic. It can be seen that while the trip transfer volumes in each 
travel-time range naturally increase with the years, the percentage 
volume in each range remains essentially constant over the years. 
Thus it may be generalized that whatever the status of the high- 
way system, the time spent in travel for a given trip purpose will 
remain approximately the same. 

A similar process was applied to both the surveyed and com- 
puted trip transfer matrices to determine the transfer volumes which 
travel given distances, in two-and-one-half-mile increments. These 
curves were also treated on both a volume and percentage basis; 
the results are shown in Exhibits T-18 and T-19, respectively. The 
correlation coefficent for the two 1945 curves is 0.99. In this 
chart are also included curves for 1959 computed traffic and 
1975 forecast traffic. It is interesting to note that on a percentage 
basis the volumes decrease in the lower ranges of travel distance 
and increase in the upper ranges with increasing years, reflect- 



Exhibit T-21 
SCREEN-LINE LOCATION MAP 



NNER BELT AND EXPRESSWAY SYSTEM 



1 1 1-3 1 



DOWNTOWN BOSTON INSET 




1 500 1500 30 00 FT. 

MAP SCALE 



ing improved travel conditions so that for a given travel time, a 
greater distance may be traveled. Also of interest is the shape 
of the curve in 1975, indicating a disproportionate increase in 
the number of trips of 15 to 20 miles length as compared to 
1959. This increase in this range may be ascribed to the growth 
and, by 1975, solid establishment of communities satellite to Bos- 
ton, and the resulting travel desires between them. 

TRIP-END COMPARISON 

The trip transfer matrices, surveyed and computed, for 1945 
were summed over rows and columns to determine the number 
of trip ends in each zone or sector, and compared as shown in 
Exhibit T-20. The correlation coefficient for comparison of sur- 
veyed and computed trip-ends per zone is 0.968 for the down- 



Exhibit T-22 
BASE YEAR AND DESIGN YEAR TRIP ENDS 




111-32 



NNER BELT AND EXPRESSWAY SYSTEM 





town zones and 0.975 for the entire 1945 Study Area. It can 
be seen that close agreement exists between the two sets of data, 
and further that there is no evidence of any systematic geographic 
error. 

SCREEN-LINE ANALYSIS 

For each major determination of parameter values a screen- 
line analysis was made. The results of these analyses for Para- 
meter Sets 70, 90, 102, and 110 are shown in Tgble T-ll. The 
screen-lines are illustrated in Exhibit T-21. It should be noted 
that the 1959 Neponset River screen-line was originally incom- 
plete in that it did not include a station at Route 128; that is, 
it stopped short of defining completely that portion of the study 
area which it is intended to isolate. The increase in traffic on the 
Southeast Expressway between 1960 and 1961 was found from 
field traffic counts to be 35%/ while other screen-line crossings 
were increasing from 3% to 6%, because a portion of Route 128 
between Route 24 and Route 37 was completed in September 
1960, thus inducing traffic which originates in the area of Ded- 
ham, Readville and points south to use the Southeast Express- 
way to get to Boston, a route to which the computer assignment 
program assigned traffic. When this Route 128 screen-line station 
is included, the resulting difference between surveyed and com- 
puted volumes crossing this screen-line is +3.8%/ as shown. 

TRAFFIC GENERATION AND DISTRIBUTION 

With the best parameter sets determined for the gravity 
model by means of statistical and screen-line analyses, the trip 
transfer volumes for the year 1975 were computed, based on 
1975 projected sociological data and the time paths of the 1975 
spider network. The geographical distribution of the generated 
and attracted trip-ends for the design year 1975 are shown in 
Exhibit T-22, together with those for the base year, 1959. As 
an indication of the travel times upon which this distribution is 



Exhibit T-23 
SURVEY YEAR AND DESIGN YEAR ISOCHRONES 



INNER BELT AND EXPRESSWAY SYSTEM 



111-33 



TABLE T-lll 
CONSOLIDATED 1975 PROJECTED TRIP 
Average Daily Traffic Between Districts 

(In Hundreds of Vehicles, To Nearest Hundred) 



TRANSFERS 



District 


1 


2 3 


4 


5 


6 


7 


8 


9 


10 


11 


12 


13 


14 


15 


16 


17 


18 


19 


20 


21 


22 


23 


24 


25 


26 


27 


28 


29 


30 


31 


32 


District 


Station 
Group 
































































Station 


NE 


117 


12 9 


9 


39 


4 


5 


20 


7 


11 


34 


8 


9 


8 


7 


8 


9 


34 


15 


7 


2 


4 


2 


11 


1 


58 


47 


2 


1 


6 


* 


3 


Group 

NE 


N 


268 


22 20 


26 


97 


11 


12 


44 


15 


22 


53 


26 


22 


20 


16 


14 


17 


65 


49 


21 


5 


8 


4 


20 


2 


34 


61 


58 


3 


13 


1 


5 


N 


NW 


228 


13 18 


30 


122 


12 


12 


42 


12 


13 


38 


33 


37 


46 


31 


17 


15 


22 


39 


67 


9 


12 


4 


16 


2 


12 


11 


5 


34 


20 


1 


7 


NW 


W 


263 


13 16 


23 


122 


22 


22 


68 


17 


12 


26 


15 


39 


53 


65 


29 


24 


21 


18 


21 


22 


24 


7 


26 


3 


10 


8 


2 


5 


203 


1 


13 


W 


SW 


155 


8 8 


10 


49 


7 


9 


39 


10 


6 


12 


6 


12 


13 


18 


30 


21 


11 


6 


6 


5 


18 


13 


30 


3 


5 


4 


1 


2 


12 


33 


64 


SW 


s 


362 


17 18 


21 


100 


15 


19 


84 


34 


13 


25 


13 


22 


23 


34 


66 


62 


22 


11 


10 


10 


35 


108 


130 


8 


10 


8 


2 


3 


16 


2 


32 


s 


SE 


269 


13 14 


15 


70 


10 


12 


54 


22 


11 


20 


10 


15 


13 


28 


29 


41 


18 


9 


7 


5 


14 


18 


165 


40 


8 


6 


1 


2 


11 


1 


11 


SE 


District 
1. 


1505 


192 80 


341 


556 


115 


185 


405 


130 272 


346 


277 


262 


131 


173 


388 


282 


278 


194 


96 


70 


139 


196 


541 


48 


108 


56 


50 


16 


80 


23 


68 


District 
1. 
2 


2. 




180 13 


23 


51 


7 


9 


24 


11 


97 


54 


21 


17 


10 


11 


19 


16 


68 


17 


7 


4 


8 


9 


30 


3 


17 


11 


3 


1 


6 


1 


4 


3. 




68 


35 


40 


7 


9 


12 


5 


28 


33 


27 


20 


9 


11 


17 


12 


24 


16 


8 


4 


7 


9 


26 


3 


8 


4 


4 


1 


5 


1 


3 


3. 


4. 






290 


380 


30 


29 


69 


16 


35 


98 


124 


78 


27 


33 


31 


24 


38 


40 


22 


10 


13 


11 


35 


3 


13 


8 


7 


4 


13 


2 


6 


4. 


5. 








945 


124 


136 


177 


31 


83 


245 


87 


253 


95 


122 


120 


77 


92 


95 


62 


40 


55 


52 


136 


14 


36 


19 


21 


10 


43 


9 


22 


5. 


6. 










159 


69 


49 


8 


10 


18 


16 


47 


22 


48 


27 


18 


12 


11 


8 


10 


13 


9 


25 


2 


5 


3 


3 


1 


11 


2 


4 


6. 


7. 












111 


117 


12 


11 


20 


17 


35 


20 


46 


49 


27 


15 


12 


8 


12 


18 


12 


31 


3 


6 


4 


3 


1 


12 


2 


7 


7. 


8. 














209 


30 


35 


53 


44 


67 


37 


65 


184 


94 


42 


33 


19 


22 


44 


49 


120 


10 


18 


9 


8 


3 


22 


6 


18 


8. 


9. 
















115 


14 


19 


15 


15 


9 


12 


30 


35 


16 


11 


6 


5 


10 


17 


54 


4 


7 


4 


3 


1 


6 


1 


5 














9. 


10. 
11. 


NO. 


DISTRICT DEFINITION 
(See Key Map) 

LOCALITY 










193 


144 
709 


38 
160 


22 
64 


12 
30 


13 
26 


19 
32 


17 
27 


117 
157 


22 
91 


10 
28 


4 
10 


8 
14 


8 
14 


27 
47 


3 

5 


21 
35 


15 
25 


3 
13 


2 
4 


7 
14 


1 

2 


4 
8 


10. 
11. 


12. 


1. 


Downtown Boston 
















251 


83 


31 


21 


21 


19 


41 


14 


31 


8 


10 


8 


28 


3 


14 


10 


9 


4 


11 


1 


5 


12. 


13. 


2. 


East Boston, Winthrop 
















408 


131 


78 


37 


26 


31 


40 


39 


19 


23 


13 


39 


4 


13 


8 


6 


7 


23 


3 


9 


13. 


14. 


3. 


Charlestown 






















449 


108 


28 


16 


19 


26 


42 


34 


31 


11 


28 


3 


9 


6 


5 


7 


29 


3 


10 


14. 


15. 


4. 


Somerville 
























481 


66 


26 


19 


19 


23 


62 


71 


16 


40 


4 


9 


5 


4 


4 


38 


5 


15 


15. 


16. 


5. 


Cambridge 


























501 


156 


27 


31 


13 


18 


105 


74 


91 


7 


12 


7 


4 


3 


19 


5 


29 


16. 


17. 


6. 


Brighton 




























492 


24 


15 


9 


8 


30 


70 


158 


9 


10 


6 


4 


2 


12 


3 


15 


17. 


18. 


7. 


Brookline 






























667 


53 


17 


7 


12 


12 


35 


5 


101 


52 


8 


3 


12 


2 


7 


18. 


19. 
20. 


8. 


Roxbury 












NO. 




LOCALITY 














737 


40 


8 


11 


7 


25 


3 


27 


26 


18 


4 


13 


2 


5 


19. 


9. 


South Boston 












21. 


Wellesley 


Weston 
















444 


11 


12 


5 


15 


2 


10 


7 


7 


8 


14 


2 


5 


20. 


21. 


10. 


Chelsea, Revere 










22. 


Dedham, 


Needham, Westwood 














241 


30 


6 


14 


1 


4 


3 


2 


3 


20 


2 


7 


21. 


22. 


11. 


Everett, Maid 


en, Me 


Irose 








23. 


Canton, Milton, Randolph 


















430 


25 


46 


4 


6 


4 


2 


3 


21 


6 


40 


22. 


23. 
24. 


12. 


Medford, Wincheste 


r 








24. 


Braintree, 


Quincy, Weymouth 


















238 


99 


5 


6 


4 


1 


1 


8 


2 


22 


23. 


13. 


Arlington, Belmont, * 


irVaierrown 






25. 


Cohasset, 


Hinqham, Hull 






















1106 


62 


19 


12 


5 


3 


19 


6 


31 


24. 


25. 
26. 
27. 
28. 
29. 
30. 
31. 
32. 


14. 


Waltham 












26. 


Beverly, Hamilton, 


Manchester, Marblehead, Salem, Wenham 














199 


2 


2 


1 


* 


3 


1 


3 


25. 


15. 


Newton 












27. 


Danvers, J 


v\iddleton, Peabody 
























797 


68 


5 


2 


7 


1 


4 


26. 


16. 


Hyde Park, Jamaica Plain, West Roxbury 




28. 


North Reading, Wilmingto 


n 


























445 


4 


1 


4 


1 


2 


27. 


17. 


Dorchester 












29. 


Concord 


































97 


1 


3 


* 


1 


28. 


18. 


Lynn, Nahant 


, Saugus, Swampscott 






30. 


Ashland, 1 


: ramingh 


am, Natick, Wayland 




























83 


3 


* 


1 


29. 


19. 


Lynnfieid, Reading, Stoneham, Wakefield, 


Woburn 


31. 


Dover, Medfield 




































1013 


3 


8 


30. 


20. 


Bedford, Burl 


ngton, 


Lexington, Lincoln 




32. 


Norwood, 


Sharon, 


Walpole 














•i». 


, *k«„ K 


-i „„i,;,i„ 
















59 


7 
297 


31. 
32. 



111-34 



NNER BELT AND EXPRESSWAY SYSTEM 




KEY TABLE FOR NETWORK 3 INTERCHANGES 




Code 




No. 


Expressway 


012 


Route 128 


061 


Interstate 95 


98 


Route 128 


99 


Mass. Turnpike 


100 


Mass. Turnpike 


101 


Mass. Turnpike 


103 


Moss. Turnpike 


141 


Route 3 


461 


Route 24 


600 


— 


601 


— 


602 


— 


603 


— 


604 


— 


605 


— 


610 


Centrol Artery 


611 


Northeast 


613 


Central Artery 


614 


Central Artery 


615 


Central Artery 


616 


Central Artery 


617 


Central Artery 


618 


Central Artery 


621 


Northeast 


622 


Northeast 


623 


Northeost 


624 


Northeast 


625 


Northeast 


626 


Northeast 


627 


Northeast 


628 


Interstate 95 


629 


interstate 95 


631 


Southeast 


632 


Southeast 


633 


Southeast 


634 


Southeast 


636 


Southeast 


637 


Southeast 


638 


Southeast 


639 


Southeast 


644 


Southwest 


645 


Southwest 


646 


Southwest 


647 


Southwest 


648 


Southwest 


649 


Southwest 


654 


Mass. Turnpike 


655 


Mass. Turnpike 


656 


Mass. Turnpike 


657 


Moss. Turnpike 


658 


Inner Belt 


659 


Mass. Turnpike 


660 


Mass. Turnpike 


661 


Route 2 


662 


Route 2 


663 


Route 2 


664 


Route 3 


665 


Route 3 


666 


Route 3 


667 


Route 3 


671 


Route 3 


672 


Route 3 


673 


Route 3 


674 


Route 3 


675 


Route 3 


681 


Interstate 93 


682 


Interstate 93 


683 


Interstate 93 


684 


Interstate 93 


685 


Interstate 93 


686 


Interstate 93 


687 


Interstate 93 


688 


Interstate 93 


691 


Inner Belt 


692 


Inner Belt 


693 


Inner Belt 


695 


Inner Belt 



Interchange 
Location 

Bass Avenue, Gloucester 
Newburyport Turnpike, Danvers 
Massachusetts Turnpike, Weston 
Washington Street, West Newton 
Centre Street, Newton 
Cambridge Street, Brighton 
Centrol Artery, Boston 
Burlington Road, Bedford 
West Street, Stoughton 
Broadway, Lynn 
Highland Avenue, Lynn 
Boston Street, Salem 
North Street, Salem 
Cobot Street, Beverly 
Loring Avenue, Salem 
Dover Street, Boston 
City Square, Charleslown 
Causeway Street, Boston 
Sumner Tunnel, Boston 
State Street, Boston 
Northern Avenue, Boston 
Congress Street, Boston 
Beach Street, Boston 
Everett Avenue, Chelsea 
Arlinglon Street, Chelsea 
Carter Street, Chelsea 
Webster Avenue, Chelsea 
Revere Beach Parkway, Revere 
Sargent Street, Revere 
Squire Road, Revere 
Andover Street, Danvers 
Center Street, Danvers 
Southampton Street, Dorchester 
Columbia Rood, Dorchester 
Freeport Street, Dorchester 
Gallivan Boulevard, Neponset 
Granite Avenue, Milton 
West Squantum Street, Milton 
Willard Street, Quincy 
Furnace Brook Parkway, Quincy 
Centre Street, Roxbury 
Morton Street, Jamaica Plain 
Cummins Highway, Hyde Pork 
West Street, Hyde Pork 
Milton Street, Readville 
Route 128, Canton 
Inner Belt, Boston 
Massachusetts Avenue, Back Bay 
Huntington Avenue, Back Bay 
Arlington Street, Boston 
Erie Street, Cambridge 
Cochttuote Road, Framingham 
Worcester Turnpike, Framingham 
Spring Street, Lexington 
Woltham Street, Lexington 
Pleasant Street, Lexington 
Route 2, Arlington 
Park Avenue, Arlington 
Pleasant Street, Arlington 
Alewife Brook Parkway, Cambridge 
Main Street, Medford 
Mystic Valley Parkway, Medford 
Massachusetts Avenue, Cambridge 
Massachusetts Avenue, Lexington 
Woburn Street, Lexington 
Route 128, Reading 
Montvate Avenue, Woburn 
Pork Street, Stoneham 
Main Street, Stoneham 
Fellsway West, Medford 
Salem Street, Medford 
Mystic Valley Parkwoy, Medford 
McGrath Highway, Somerville 
Southwest Expressway, Roxbury 
Brookline Avenue, Boston 
Beacon Street, Boston 
Harvard Street, Cambridge 



Code 




No. 


Expressway 


696 


Inner Belt 


697 


Inner Bell 


698 


Inner Belt 


701 


Route 128 


702 


Route 128 


703 


Route 126 


704 


Route 128 


705 


Route 128 


706 


Route 128 


707 


Route 128 


708 


Route 128 


709 


Route 128 


710 


Route 128 


711 


Route 128 


712 


Route 128 


713 


Route 128 


714 


Route 128 


715 


Route 128 


716 


Route 128 


717 


Route 128 


718 


Route 128 


719 


Route 128 


721 


Route 128 


722 


Route 128 


723 


Route 128 


724 


Route 128 


725 


Route 128 


726 


Route 128 


727 


Route 128 


728 


Route 128 


729 


Route 128 


730 


Route 128 


731 


Route 128 


732 


Route 1 28 


733 


Route 128 


734 


Route 128 


740 


Route 128 


741 


Route 128 


742 


Route 128 


743 


Route 128 


744 


Route 128 


745 


Route 128 


746 


Route 128 


747 


Route 128 


748 


Route 128 


749 


Route 128 


750 


Route 128 


751 


Route 128 


819 


Inner Belt 


820 


East Boston 


821 


East Boston 


822 


— 


823 


Interstate 95 


824 


Interstate 95 


825 


Interstate 95 


826 


Interstate 95 


827 


Interstate 95 


828 


Interstate 95 


829 


Interstate 95 


831 


Southeast 


832 


Southeost 


833 


Southeast 


834 


Southeast 


835 


Southeast 


841 


Interstate 95 


842 


Interstate 95 


843 


Northwest 


862 


Northwest 


863 


Northwest 


866 


Route 2 


867 


Route 2 


868 


Route 2 


881 


Interstate 93 


882 


Interstate 93 


883 


Interstate 93 


894 


Inner Belt 



Interchange 
Location 

Northwest Expressway, Somerville 
Interstate Route 93, Somerville 
Prison Point Bridge, Charleslown 
Route 1 , Lynnfield 
Wolnut Street, Lynnfield 
Charles Avenue, Wakefield 
Vernon Street, Wakefield 
Solem Street, Wakefield 
North Avenue, Wakefield 
Main Street, Reading 
Washington Street, Woburn 
Main Street, Woburn 
Winn Street, Burlington 
Cambridge Street, Burlington 
Middlesex Street, Burlington 
Route 3, Burlington 
Bedford Street, Lexington 
Marrett Road, Lexington 
Route 2, Lexington 
Trapelo Road, Waltham 
Winter Street, Waltham 
South Avenue, Weston 
Washington Street, Newton 
Worcester Turnpike, Wellesley 
Highland Avenue, Needham 
Great Plain Avenue, Needham 
West Street, Dedham 
High Street, Dedhom 
Route 1 , Dedhom 
East Street, Westwood 
Railroad Station 128, Dedham 
Washington Street, Canton 
Ponkapoog Trail, Milton 
Foil River Expressway, Randolph 
North Main Street, Randolph 
Granite Street, Broinlree 
Andover Street, Peobody 
Lowell Street, Peabody 
Weston Street, Woltham 
Endicotf Street, Danvers 
High Street, Danvers 
Eliot Street, Danvers 
Dodge Street, Beverly 
Brimbal Avenue, Beverly 
Essex Street, Beverly 
Hort Street, Wenham 
Pine Street, Manchester 
School Street, Manchester 
Southeast Expresswoy, Boston 
Airport Rood, East Boston 
McClellan Highway, East Boston 
Beach Street, Revere 
Salem Turnpike, Saugus 
Ballard Street, Saugus 
Wolnut Street, Lynn 
Waycross Road, Lynn 
Lynnfield Street, Lynn 
Route 128, Peabody 
Lowell Street, Peabody 
Route 128, Braintree 
Washington Street, Braintree 
Union Street, Braintree 
Main Street, Weymouth 
Derby Street, Hingham 
Coney Street, Walpole 
Neponset Street, Norwood 
Concord Avenue, Cambridge 
Massachusetts Avenue, Cambridge 
Beacon Street, Somerville 
Bedford Road, Lincoln 
Cambridge Turnpike, Concord 
Elm Street, Concord 
Lowell Street, Wilmington 
Concord Street, Wilmington 
Middlesex Street, Wilminglon 
Northeast Expressway, Boston 



Exhibit T-24 
DISTRICT AND INTERCHANGE KEY MAP 



INNER BELT AND EXPRESSWAY SYSTEM 



111-35 



Item 



Total Trips 

Vehicle-Hours 

Vehicle-Miles 

Maximum 

Travel Time, hours 

Average 

Travel Time, hours 

Maximum 

Travel Distance, miles 

Average 

Travel Distance, miles 

Average Speed, mph 





TABLE T-IV 










STATISTICAL DATA 










Year & Mode 






1945 Survey 


Model-Survey 
1945 Model Difference 


1959 Model 


1975 Model 


1959-1975 
Increase 


796,101 


800,085 +0.5% 


2,409,842 


3,745,988 


55% 


172,306 


193,936 +13% 


538,655 


974,724 


81% 


3,250,055 


3,776,070 +16% 


12,350,541 


29,614,661 


140% 


1.4 


1.4 


1.2 


1.6 


33% 


0.22 


0.24 +9% 


0.22 


0.26 


18% 


30.0 


32.5 + 8% 


40 


50 


25% 


4.08 


4.72 +16% 


5.13 


7.91 


54% 


18.9 


19.5 + 3% 


22.9 


30.4 


33% 



based, Exhibit T-23 shows the time-distance contours (isochronic 
lines) of the 1975 spider network, including expressways. As a 
basis for comparison of travel times without expressways, the 
1945 isochronic lines are also included therein. 

A consolidated trip transfer matrix for 1975 is presented in 
Table T-lll, while a key map for this matrix is illustrated in Exhibit 
T-24. Table T-IV summarizes the major statistical data of the fore- 
going statistical analysis, together with comparable data for the 
base year 1 959 and the design year 1 975. 

TRAFFIC ASSIGNMENT 

INTRODUCTION 

The National Policy of the American Association of State 
Highway Officials is generally recognized as the primary guide 
to the methods and procedures for the purpose of determining 
traffic assignments to be used as the basis for design of express- 
way-type facilities. There follows below a comparison of the pro- 
cedure described therein with those which were required by virtue 
of the use of the mathematical model. 



As indicated in the National Policy, (BI) the first step was the 
"establishment of all motor-vehicle trips and their desire lines in 
the area for a representative day during the current year." This 
data was arrived at by considering trips and desire lines for 
the year 1945, and determining methods of expansion which, 
when applied to this data, would provide acceptable values for 
screen-line crossings as compared with actual field-survey values 
in the base year; the expansion was effected by means of the 
gravity model previously described. 

At the same time that the first step was being carried out, 
work was also being carried forward on the second step, the 
"preliminary location and design studies for the arterial high- 
way," hereinafter referred to as initial basic design. The third step, 
the "determination of traffic growth factors" is, of course, an in- 
tegral part of the development of the gravity model, and as such is 
expected to be subject to a much smaller range of error than would 
be the case under other methods in current usage. This smaller 
range is due to the fact that almost all of the forecasting is applied 
to the sociological data cited above, the growth of which is much 



more accurately predictable. The "expansion of current zone-to- 
zone travel to the future year" is a direct result of the completion 
of the gravity model for the base year and its application to the 
projected sociological data of the future year. 

The fourth step, the "assignment of the expanded daily 
trips to the arterial highway improvement" was also under- 
taken as stipulated in the National Policy, by initially "superim- 
posing on an area map which shows all existing facilities, the 
location and preliminary design of the arterial in question, as 
well as the other highway improvements contemplated during the 
period of time designated for design." The use of the gravity 
model required, of course, that this step be taken as early as 
possible, and as noted above it was actually accomplished con- 
currently with the first step. 

Immediately thereafter the second item in the assignment 
step, i.e., the estimation of "the overall speeds of traffic on the 
contemplated improvements ... on the basis of experience on 
comparable facilities," and the determination of "actual overall 
speeds and travel times on existing facilities ... by field sur- 
veys," was undertaken and completed. At this point all data 
had been accumulated which were necessary for the traffic as- 
signment. 

FREE ASSIGNMENT 

The basic assignment of traffic for the subject Study was 
undertaken by making use of the all-or-none method, illustrated 
as a diversion curve in Exhibit T-2, to indicate its relationship to 
those used by others. This process assigns all traffic between 
any single pair of origin and destination points to the least-travel- 
time route. 

In view of the information collected on diversion procedures, 
it is evident that free assignment traffic volumes, or volumes de- 
termined by assignment on an all-or-none basis, as illustrated in 
Exhibit T-25, represent the future potential demand for express- 
way service and are not to be construed as expected express- 
way traffic. 

The free assignment figures arrived at for the year 1975 
are, however, reliable predictions of the manner in which traffic 



111-36 



NNER BELT AND EXPRESSWAY SYSTEM 



Ob 



Li 




VOLUME SCALE 
UN THOUSANDS) 



STANDARD METROPOLITAN AREA LIMIT 
— O— INTER- EXPRESSWAY INTERCHANGE 
— O Z.O«i SERVICE INTERCHANGE 

INTERCHANGE CODE NUMBER 

FREE ASSIGNMENT 
EXPRESSWAY ADT CAPACITY 




will desire to move if the necessary facilities are available, based 
upon the potential growth of the entire metropolitan community. 
To the extent that such facilities are not made available, such 
growth will be retarded, and the central cities will be gradually 
depleted in favor of the suburbs. 

The question naturally arises as to whether the existing ar- 
terial streets will be able to carry those volumes which are beyond 
the proposed capacities of the expressways. The answer can be 
determined quite readily by dividing the study area into segments 
as follows: from the Central Business District radial lines are drawn 
roughly midway between radial expressways, in such a way as 
to define the boundaries of the area of influence of each radial 



Exhibit T-25 
1975 FREE ASSIGNMENT VOLUMES 



INNER BELT AND EXPRESSWAY SYSTEM 




111-37 



expressway; each of these pie-shaped sectors is then a "corri- 
dor" served by the radial expressway which bisects it. Then 
around the Central Business District, and at varying distances from 
its center, roughly circular boundaries are described, which divide 
the area into cordon rings, as shown in Exhibit T-26. The desire 
for radial traffic movement, as shown by the free assignment at 
each cordon in each corridor may then be compared with the total 
of the arterial and expressway capacity at this cordon line; the 
difference between the two is the surplus or deficiency in the total 
capacity of the corridor to carry the projected radial traffic. 

The capacity per hour of each major street was estimated 
on the basis of existing physical and traffic conditions, and com- 
pared for verification wherever possible with available traffic 
counts. The capacity per hour of each expressway was deter- 
mined as explained hereinafter. 

The Cordon-Corridor Analysis results, shown in Table T-V, 
indicate the amount of capacity deficiency at each cordon line in 
each corridor of influence of the radial expressways, on the above- 
noted basis. It is apparent that the capacities of facilities presently 
proposed or provided are grossly deficient in their ability to provide 
for the indicated traffic volumes. It should be evident that the 
proposed system of expressways, without the provision of aux- 
ilary facilities or the improvement and extension of existing trans- 
portation facilities, will be inadequate in serving to foster the 
healthy growth of the Boston Metropolitan Area assumed at the 
outset of this Study. At the same time, elementary consideration 
of the traffic volumes presented yields the conclusion that an 
attempt to provide for these movements solely by the construction 
of additional expressways would result in a prohibitively expensive 
and impractical system. 

TISRO ASSIGNMENT PROCEDURE 

The free assignment of traffic to the Expressway System 
resulted in traffic volumes far in excess of available capacity on 
practically the entire system. While the free assignments were 



Exhibit T-26 
CORDON-CORRIDOR LOCATION MAP 




111-38 



NNER BELT AND EXPRESSWAY SYSTEM 




based on a proven principle, i.e., all-or-none, for obtaining assign- 
ments which indicate desires, it was obvious that a far more 
sophisticated method of assignment would be necessary to obtain 
traffic volumes for design purposes. 

With a desire for use which is much greater than the capacity 
of the Expressway System, and with the number of expressways 
predetermined and the location of each component expressway 
confined to a rather narrow corridor by terminal location controls, 
it followed that the exact location of each expressway would 
be relatively independent of the assignment. Therefore, the pri- 
mary function of the assignments was to provide information upon 
which the design of the local interchanges could be predicated. 

The method to be used to obtain assignments had to reflect 
the following requirements: 

a. The volume assigned to any expressway link must not 
exceed the design capacity of an eight-lane expressway. 

b. The assignments must reflect average driver behavior 
to the extent that such behavior is rational and may be 
stated in mathematical terms compatible with the model 
system. 

c. The method used must be comprehensive enough to pro- 
vide sufficient information upon which the design of local 
interchanges may be predicated. 

Investigation revealed that somewhat similar problems had 
been programmed for electronic computer application elsewhere, 
but that either the basic conditions were completely dissimilar, or 
that sufficient progress of development had not been achieved 
to warrant adoption without some reservation. Major research 
effort, currently in progress by several organizations, is directed 
to the accurate simulation by electronic computer of actual traffic 
flow. However, the simulation of the actual distribution of traffic 
flow on all streets and highways within a metropolitan area would 
require computer storage of a number of alternative paths be- 
tween each origin and destination together with their travel times 
and distances. These paths could then be incrementally loaded 
with the desire traffic, and the travel times and distances on each 
link in the network would then have to be recomputed as a func- 
tion of link loading. These sets of data would have to be recon- 



Desi 


re 


— Capacity 


= Defl< 


:iency 


Corridor 




Northeast 


Desire 




Capacity 




Deficiency 


Northern 


Desire 




Capacity 




Deficiency 


Northwest 


Desire 




Capacity 




Deficiency 


Western 


Desire 




Capacity 




Deficiency 


Southwest 


Desire 




Capacity 




Deficiency 


Southeast 


Desire 




Capacity 




Deficiency 



TABLE T-V 
CORDON-CORRIDOR ANALYSIS 

Cordon 



Inner 


Intermediate 


Outer 


352,200 


281,000 


242,000 


191,000 


235,500 


115,000 


161,200 


45,500 


127,000 


258,300 


215,100 


165,000 


184,200 


186,000 


147,100 


74,100 


29,100 


17,900 


257,500 


213,700 


193,900 


193,200 


197,500 


183,800 


64,300 


16,200 


10,100 


291,200 


279,400 


225,400 


214,200 


270,000 


193,300 


77,000 


9,400 


32,100 


303,400 


322,100 


206,500 


236,400 


227,000 


160,800 


67,000 


95,100 


45,700 


341,000 


322,400 


298,100 


177,000 


155,000 


166,800 



164,000 



167,400 



131,300 



ciled on a cyclical iterative basis, since the trip desires would be 
influenced by changes in travel times, and the link loadings would 
in turn be directly affected by resulting trip desires. The trip 
desires then would indicate either drastic reductions in desired 
average length of trips or the complete elimination of many de- 
sires. Although of extreme value in the operational phases of 
traffic engineering, this type of approach, if used, would have 
ultimately yielded: 

a. the future restricted trip desires and required local inter- 
change service, on the basis that no additional express- 
ways or arterials are to be provided, i.e., using the pre- 
conceived fixed network, 

b. the future traffic volumes as limited by the fixed capac- 
ities of this network, and 



c. the speeds at which these volumes would travel. 

In essence this information would indicate the limited addi- 
tional growth of the Boston Metropolitan Area necessary to attain 
the capacity of this fixed network, and would ignore any of the 
growth to be derived from the socio-economic potential which has 
been forecast. Furthermore, under such an approach the travel 
desires based on the forecast of the 1975 socio-economic data 
would be curtailed rather than assigned to alternate paths, and 
the assignment to the alternate paths, therefore, would not be 
available for examination and use in planning of additional fa- 
cilities. 

In order to overcome the difficulties and weaknesses of such 
a flow-simulation method, two possible procedures, which may 
be described as follows, were seriously considered: 

a. Systematic reduction of the assumed speeds on each 
link of the Expressway System so as to increase travel 
time on all those links for which the free assignment is 
in excess of capacity. The systematic adjustment of speed 
would be iterative and would continue until the volume 
assigned to each link of the system was equal to or less 
than the capacity of the link. With an increase in travel 
time on the expressway links, travel over the existing 
street net would require less time for a larger number 
of the shorter length trips and hence the volumes as- 
signed to the Expressway System would be less than 
those obtained by free assignment. 

b. Selection of reasonable values for speed on the various 
expressway links and the local street network and assign- 
ment of trips to the Expressway System in rank order of 
greatest time saved per trip via the Expressway System 
as compared to the local street network. 

Both methods would yield valid expressway design assign- 
ments since they would eliminate from the Expressway System those 
trips with the least time saving, and the ramp assignments obtained 
would realistically reflect the use of the Expressway System by 
trips of sufficient length to justify its construction. 

However, in regard to the first method, it was judged that 
such an iterative procedure may not be convergent, due to the 



NNER BELT AND EXPRESSWAY SYSTEM 



111-39 



great number of links on which the speed would require adjust- 
ment, and due to the necessarily arbitrary speed reduction to be 
applied in proportion to the traffic volume on each link. Hence, 
the amount of time required to achieve a solution of the problem 
on an electronic computer could well have been excessive. In 
effect, this greater length of "machine time" would be spent to 
determine a value for that speed on each link of the Expressway 
System which, if increased, would result in congestion on the link 
because the assigned volume would then exceed the capacity. A 
different value for speed would be obtained for each link of the 
Expressway System; these values would have little use in the design 
process, and hence would be of academic interest only. 

The second method considered would achieve the desired 
result without recourse to an iterative procedure, and hence would 
result in much less "machine time." Since it was not possible to 
make a reasonable estimate of the number of iterative steps which 
would be required to obtain a solution by the first method, and 
furthermore, since the second method would be equally capable of 
providing information for the design of local interchanges and 
frontage roads, and for the recommendation of supplemental facil- 
ities, the obvious choice became the second method outlined above. 

The Time-Saving-Ran k-Order method, referred to as the 
"TISRO" method, was therefore developed and utilized as the 
basis for expressway design assignments. A detailed description 
of the theory of the TISRO assignment procedure is contained in 
Section 2 of Traffic Analysis and a description of the input and 
output of the computer program is contained in Section 3 under 
"TISRO Assignment Program." 

Aside from the development of computer programs to obtain 
the TISRO assignments, a basic step involved the establishment 
of capacity volumes for each link of the Expressway System in 
order to set a limit for the volume to be assigned to each link. 
The capacity of each expressway included in this Study was based 
upon eight lanes of width, four lanes in each direction. The num- 
ber of lanes on proposed expressways not included in this Study 
was supplied by the Department of Public Works, and the capacity 
of the existing Central Artery, the Southeast Expressway and the 
Northeast Expressway was based on six lanes. Direct connectors 



of major expressway interchanges and local interchange ramps 
were not restricted in capacity in order to obtain assignments 
which could be used as a basis for the design of these elements 
of the Expressway System. 

For design purposes, the basic lane capacity was assumed 
to be 1500 vehicles per hour, a value applicable to urban express- 



AVERAGE DAILY TRAFFIC DESIGN CAPACITY 

BASIC LANE CAPACITY : 1500 VEHICLES PER HOUR 



NO. OF LANES 



8\6\4 



160 ISO 80 



150 }I25 



120 



100 



90 



70 



975 



90 



82.5 



75 



67.5 45 



65 



60 



55 



50 



0.03 



LEGEND 

K-RATIO OF DHV TO ADT 
D=RATI0 OF DOHV TO DHV 
T= TRUCKS AS % OF DHV 




0.04 



0.05 0.06 

COMBINED RATIO. K'D 



0.07 



0.08 



Exhibit T-27 

ways with full control of access. Two-way average daily traffic 
(ADT) capacity was found on the basis of the AASHO formula: 



c 



100 P 



100 +T(j-1 



5000N 
KD 



where 



C = two-way ADT capacity, 
P = lane capacity of 1 500 vehicles per hour, 
T = percentage of trucks, 
j = equivalent number of passenger vehicles for each 

truck, taken as 2 for level terrain, 
K = design hour volume as a percentage of ADT, 



D = directional distribution during design hour as a 
percentage, 
and N = total number of lanes. 

The values noted above were introduced into the formula 
and the curves of Exhibit T-27 were constructed for convenience. 
On the basis of observation of the operation of existing express- 
way facilities, projected rational values were chosen for K, D, 
and T, and on this basis ADT capacities for each section of the 
Expressway System were then determined. Values for the ADT 
capacity of each section of the Massachusetts Turnpike were 
derived directly from data published by the Turnpike Authority; 
these Turnpike capacity figures are considerably lower than those 
used for free expressways of the same number of lanes. 

TISRO assignments were obtained for three separate net- 
works of the Expressway System. The three networks which were 
used are described earlier in this Section of the Study, and are 
shown in Exhibit T-6. Typical controlling values and the resulting 
expressway capacity restraints used in the TISRO assignment pro- 
cedure for Net 3 are indicated in Exhibit T-28. Specifically, de- 
sign capacities used for the Expressway System are as follows: 

a. The Central Artery: 1 22,000 vehicles per day. 

b. The Northeast and Southeast Expressways at the Central 
Artery: 98,000 vehicles per day. 

c. The Inner Belt: 162,000 vehicles per day. 

d. Each radial expressway included in this Study, at its 
junction with the Inner Belt: 132,000 vehicles per day. 

The trip transfer matrix previously described as the output 
of the gravity model was used as input for the TISRO assignment 
program. The TISRO method first lists trip transfers in order of 
time-saving, from greatest to smallest. The transfers are then 
assigned to the expressways up to the capacity limit of the express- 
way, or the free assignment value, whichever is less. As each 
transfer in the electronic computer process is about to be loaded 
on a link, the total loading which would result is compared with 
the stipulated capacity. If the resultant loading were to be greater 
than capacity, that transfer is not loaded, and furthermore, it 
is removed from all previous expressway links to which it was as- 
signed. It is instead assigned to the quickest alternate street path. 



111-40 



NNER BELT AND EXPRESSWAY SYSTEM 






INNER 



Other transfers with lesser time-savings may then be loaded on 
that expressway link if they do not cause the volume on that ex- 
pressway link, or any other link, to exceed capacity. When an 
expressway link has thus been loaded to capacity, any other trans- 
fer which would use that link and has lesser time-saving than those 
already loaded is then also assigned to the street system. 

ANALYSIS OF TISRO ASSIGNMENT RESULTS 

Exhibit T-29 shows the volumes of 1975 traffic as related 
to time-savings, which are assigned to the 1975 Network 3 under 
free assignment, and which remain on expressways under TISRO 
assignment. The difference between the two is assigned to the 



Exhibit T-28 
TRAFFIC FACTORS AND APPLIED CAPACITY RESTRICTIONS 



INNER BELT AND EXPRESSWAY SYSTEM 



111-41 











TRIP TRANSFERS BY TIME-SAVINGS 








150 










140 

iZO_ 

1 100 




























1 


5 




1975 PROJECTEO TRAFFIC 








-T^ 
























i 










LEGEND 

REE ASSIGNMENT 
'RESSWAY VOLUMES 

SRO ASSIGNMENT 

'RESSWAY VOLUMES 














^ r ; 












tMU 


























1 

£ 60 

20_ 


$$SS§^ 


















































-• 


















\XX\N\XXXXX\XV 


^ 


































































3 

































? 


0.2 04 0.6 0.8 1.0 


TIME - SAVINGS , HOURS 



Exhibit T-29 



street network exclusive of the expressways. It may be noted 
that all trip transfers having a time-saving of 0.36 hours (21.6 
minutes) or greater are assigned to the expressways; these com- 
prise a volume of 222,973 trips per day. Of those trip transfers 
having potential time-savings of one to about twenty minutes, 
from one-third to two-thirds are assigned to the expressways, re- 
spectively, for an additional volume of 818,306 trips per day. 
A summary of assignments of 1975 traffic appears in Table T-VI. 
The total number of trip transfers in the Standard Metropolitan 
Area matrix is 66,677 (comprising 3,745,988 trips per day in 
1975), including 231 intra-zone transfers (comprising 911,963 
trips per day in 1975) which are not assigned to the network by 
the assignment model. The remaining 66,454 interzonal transfers 
include 16,948 external station-to-zone transfers and 49,506 
zone-to-zone transfers. Of these external station-to-zone and 
interzonal transfers, about 5,000 have no quicker path by the 



expressway route, and are therefore assigned to the street net- 
work only. The remainder are loaded under free assignment to 
the expressway-plus-street paths. Under TISRO assignment, how- 
ever, those which are excluded from the expressways because of 
the capacity restraints are reassigned to the street network. These 
transfers, together with the transfers which have no quicker ex- 
pressway path, make up the TISRO street-assigned trips. 

Exhibit T-30 shows the assignment of the 1959 computed 
trip transfer matrix volumes to the 1975 Network 3 as related to 
time-savings. This assignment indicates the manner in which the 
Expressway System would be used, under the TISRO hypothesis, 
if it existed at the present time. Since a volume of only 132,307 
trips per day in 1959 saves 0.36 hours or more by the Express- 
way System, as compared with 222,973 trips per day in 1975 
with the same time-savings, a greater proportion of trips with 
lesser time-savings are assigned to the expressways in 1959 than 
are assigned in 1975, in order to utilize the capacity stipulated 
for each expressway link to the fullest extent compatible with 
the trip transfer volume matrix. Thus, for 1959 all transfers with 
time-savings greater than 0.28 hours (16.8 minutes), a volume of 
282,625 trips per day, are assigned to the expressways, and of 
those with potential time-savings less than 0.28 hours, an additional 
volume of 663,282 trips per day are assigned to the expressways. 
Table T-VI itemizes the assignment of 1959 traffic to the Express- 
way System. 

The volume of both 1959 and 1975 expressway assigned 
trips, in terms of percentage of all trip desires, falls within the 
range (27% to 58%) indicated by Smith (60) as the probable 
extent of future expressway usage in urban areas. The proposed 
Expressway System, consisting of eight-lane expressways, is ade- 
quate for only a comparatively small part of the total of all future 
potential desires, and as a result, the ratio of trips per day using 
the expressway to total trips per day in the Boston Metropolitan 
Area is at the low end of that range. The TISRO assignments of 
both 1959 and 1975 traffic to each individual expressway of 
Network 3 are illustrated in Exhibit T-31. 

A critical link is defined as that link on a given expressway 
for which the free assignment desire is in the maximum range 



and the TISRO assigned volume equals the stipulated design ca- 
pacity. The critical link for the 1975 assignments on each radial 
expressway is the section adjacent to the Inner Belt. Critical 
links also occur on the Central Artery between the Mystic River 
Bridge and the Sumner Tunnel, and between the interchange with 
the Massachusetts Turnpike near South Station and the Southeast 
Expressway. The critical links restrict the full usage of other por- 
tions of the system, in some cases to a volume far less than capac- 
ity. In particular, the section of the Inner Belt between the South- 
west and Southeast Expressways has been assigned a two-way 
total volume of 62,000, or only 38% of its stipulated design 
capacity. Reference to Exhibit T-31, however, reveals that the 
adjacent section of the Central Artery is carrying its full design 
capacity, as is the adjacent section of the Southeast Expressway. 
It is evident that under any rational assignment procedure no 
more traffic may be assigned to this Inner Belt section without 



TRIP TRANSFERS BY TIME-SAVINGS 



1959 COMPUTED TRAFFIC 




FREE ASSIGNMENT 
EXPRESSWAY VOLUMES 

TISRO ASSIGNMENT 
EXPRESSWAY VOLUMES 



0.4 0.6 0.6 

TIME - SAVINGS , HOURS 



Exhibit T-30 



111-42 



INNER BELT AND EXPRESSWAY SYSTEM 




the provision of additional capacity parallel to these other facili- 
ties. This matter is further discussed in Section 4. 

At each junction of a radial expressway with the Inner Belt, 
the radial is carrying a traffic load equal to its design capacity, 
which without the provision of additional lanes on the radial, pre- 
cludes the use of adjacent portions of the Inner Belt to full capacity. 
It is evident that the volumes assigned to these less-than-capacity 
sections might be increased by changing the stipulated values of 
K, D and T. The values used for K, D and T resulted, as noted 
earlier herein, in a capacity of 162,000 vehicles per day for the 
Inner Belt, and of 132,000 vehicles per day for the proposed 
radial expressways at their junctions with the Inner Belt, although 
the number of lanes are identical. However, since empirical data 
collected for the existing expressways indicates that the design 
hour volume in each direction on the Inner Belt will be more 
nearly equal than the design hour volume on the radials, and that 
the radials will carry a somewhat larger proportion of their daily 
traffic in the design hour than will the Inner Belt, this difference 
in capacity as noted above is reasonable. The selected values 
of K and D are based on these conclusions and projections of 
future expressway use, and it is considered that any revision of 
these values would not be warranted. 

It is also evident that the value of lane capacity used for 
design is less than volumes which have been measured on exist- 
ing urban expressways. However, such higher values could not 
be used in design, nor could the fact that the number of lanes 
actually used for travel is greater than the number of lanes de- 
signed for travel be considered in the determination of design 
capacities. The values adopted and used for this Study are con- 
sidered sound, and the numerical solutions obtained are reasonable 
and may be used as an important guide in understanding the 
complexity of traffic movements on this Expressway System of 
pre-determined capacity. 

An indication of the results which might be obtained by in- 
creasing the capacity of the radial expressway sections adjacent 
to the Inner Belt is, by coincidence, available in the results of the 
TISRO assignment to the Massachusetts Turnpike. At the junction 
of the Inner Belt and the Turnpike, the Inner Belt capacity re- 



TABLE T-VI 
ASSIGNMENTS TO 1975 HIGHWAY NETWORK 

1959 COMPUTED TRAFFIC 



1975 PROJECTED TRAFFIC 



Type of Traffic 

All Trips 

Infra-zonal Trips 

Inter-zonal Trips 

Street-Alone Trips 

Free-Assignment 
Expressway Trips 

TISRO-Assignment 
Expressway Trips 

Expressway- 
Excluded Trips 

Street-Alone Trips 

TISRO Street- 
Assigned Trips 



Volume 


% of 
Total 

100% 


% of 
Interzonal 


Volume 


% of 
Total 

100% 


% of 
Interzonal 


2,849,695 


— 


3,745,988 




884,000 


31% 


— 


911,963 


24% 


— 


1,965,695 


69% 


100% 


2,834,025 


76% 


100% 


539,554 


19% 


27% 


902,273 


24% 


32% 


1,426,141 


50% 


72% 


1,931,752 


52% 


68% 


945,907 


33% 


48% 


1,041,279 


28% 


37% 


480,234 


17% 


24% 


890,473 


24% 


31% 


539,554 


19% 


27% 


902,273 


24% 


32% 



1,019,788 



36% 



52% 



1,792,746 



48% 



63% 



mains, as elsewhere, at 162,000 vehicles per day, while the Turn- 
pike stipulated capacity is 108,000 vehicles per day. At the 
approach to the Inner Belt, however, the TISRO assignment to 
the Turnpike is 87,500, or only 81 % of capacity, while the Inner 
Belt is carrying an assigned volume of about 115,000 vehicles 
per day, or 71 % of capacity. In this case the six-lane section 
of the Turnpike between Interchange 99 at West Newton and 
Interchange 100 at Newton Corner is assigned the full capacity 
volume of 80,000 vehicles per day, thus precluding any further 
assignment to the section of the Turnpike adjacent to the Inner 
Belt, except that 7,500 shorter trips make use of the section 
adjacent to the Inner Belt. If, by some acceptable rationaliza- 
tion, the design capacities on the proposed radial expressways 
at their junction with the Inner Belt were to be increased to equal 
that of the Inner Belt, it would probably be found that a similar 
situation would develop. An expressway section farther out on 
the radial could be carrying capacity traffic, while that section 
adjacent to the Inner Belt could be below capacity. It is generally 



true that the per-lane efficiency of use of roadways wider than 
four lanes in each direction drops off sharply. The width of road- 
ways contemplated in these areas is four lanes; alteration of the 
values of K and D in a manner to indicate a need for more than 
four lanes would thus be self-defeating. 

With these and related considerations in mind, a preliminary 
analysis was made of the TISRO assignment of traffic to the three 
networks presented to the computer. It was confirmed that these 
assignments would be entirely adequate for use as a basis upon 
which the design assignments could be established. It is evident 
that valid rational procedures other than the TISRO method could 
be developed, such as requiring that alternate expressway paths 
be used as well as the alternate street path, but analysis of the 
results of the TISRO assignments indicates that such refinements 
would, with regard to the Expressway System, change only the 
nature of the transfers assigned to the system, and not materially 
affect the volumes assigned to either the expressways or the ramps 
in that portion of the system involved in this Study. 



INNER BELT AND EXPRESSWAY SYSTEM 



111-43 




Exhibit T-31 
BASE YEAR AND DESIGN YEAR TISRO ASSIGNMENTS 




VOLUME SCALE 
(IN THOUSANDS) 



LEGEND 
STANDARD METROPOLITAN AREA LIMIT 
INTER-EXPRESSWAY INTERCHANGE 
— e— LOCAL SERVICE INTERCHANGE 
O00 INTERCHANGE CODE NUMBER 
|p'-'-^ 1939 TISRO ADT ASSIGNMENT 
ggjftgg 1975 TISRO ADT ASSIGNMENT 

EXPRESSWAY ADT CAPACITY 



111-44 



INNER BELT AND EXPRESSWAY SYSTEM 



SECTION 4 - DESIGN ASSIGNMENTS 



BOS 



>. 



O 



INTRODUCTION 

The TISRO assignments as obtained from the computer op- 
erations pertained specifically to the three expressway networks 
which were selected for electronic computation. As previously 
noted, these networks were chosen on the basis that interpolation 
of the TISRO assignments would yield traffic volumes applicable 
to any of the alternative locations studied. Furthermore, in order 
to arrive at values of assigned traffic for design purposes, three 
factors were given consideration. First, the general location and 
relative amount of local service provided by the networks had 
to be maintained. Second, in some cases, the TISRO assignments 
to ramps required refinement in order to obtain a valid design 
of the local interchanges. Third, the resulting average daily traffic 
had to be converted to design hour volumes. 



FACTORS IN DETERMINATION OF 
ASSIGNED TRAFFIC VOLUMES 

GENERAL LOCATION AND AMOUNT OF LOCAL SERVICE 

The general location and extent of the expressway networks 
selected was predetermined by the terminal control points, the 
corridors of location, and the scope of this Study. The relative 
amount of local service provided by each network was derived 
from basic designs of alternative locations so as to obtain the 
optimum local service for the recommended basic design. Sub- 
stantial departures in the recommended basic design, from either 
the general location or the amount of local service, would require 
a completely revised set of assigned volumes throughout the net- 
work. The final assignments to the Expressway System were there- 
fore based on the original assumptions as to the number, loca- 
tion and capacities of the expressways, which served as a basis 
for the networks used in the TISRO assignments, even though these 
assignments indicated the necessity for augmented expressway 
capacity. 

REFINEMENT OF TISRO RAMP ASSIGNMENTS 

The TISRO program permitted the assignment of unrestricted 



ramp volumes up to the limit imposed by the design capacity 
available on the expressway. Analysis of the TISRO assignments 
to the three networks indicated that the ramp assignments at a 
limited number of proposed locations were substantially higher 
than those generally accepted for single-lane ramp design. Con- 
tributing volumes to and from nodes adjacent to ramp locations 
were sub-divided in order to yield ramp design assignments com- 
patible with the expressway design assignments. The output from 
computer reports 5, 6 and 7 provided the means for the refine- 
ment of ramp loadings. These reports contain full details of every 
trip-transfer in the system, as follows: 

Report 5 — Lists of expressway-assigned positive time saving 
transfers by origin and destination. 

Report 6 — Lists of trip transfers in which the links of each 
minimum path are presented in order of use. 

Report 7 — Lists of the incremental load on each link from 
each trip transfer. 

Zone volumes were extracted by means of reports 5, 6 and 
7, and then subdivided and proportioned into the sectors com- 
prising the zone on the basis of the land use and population of 
each sector. These sector volumes were then manually re-assigned 
to serve as the basis for determinations of average daily traffic 
volumes for location and design of the various interchanges. 

AVERAGE DAILY TRAFFIC 

For each expressway studied, the basic design which pro- 
vided the most favorable features of location, cost and potential 
traffic service was selected and assignments were made to the 
local interchanges, which in turn were evaluated on the basis of 
the optimum desired traffic service. Necessary adjustments, where 
practicable, were made to the basic design without compromising 
the expressway design standards. At some locations, especially 
along the Inner Belt, the traffic potential to a particular area was 
greater than the design volume allowable on a single-lane ramp. 
In these cases, a higher type of interchange design was considered, 
but it was found that this treatment would induce greater traffic 
volumes than could be accommodated by the local street system. 
The recommended solutions included additional single-lane ramps 



to provide the necessary traffic service. After modifications to the 
basic design were incorporated to provide optimum traffic service, 
final assignments to the Recommended and Alternate Locations 
were made, resulting in the average daily traffic (ADT) volumes 
shown on the traffic schematic diagrams and the Basic Design 
Exhibits. 

DESIGN HOUR VOLUMES 

Determination of the ADT volumes for each segment of the 
expressways and for the ramps was followed by computation of 
the design hour volumes (DHV), which are dependent upon ADT 
volumes. This computation consisted of two parts: 

a. Calculation of expressway DHV's, 

b. Deriving from empirical data a relationship between ex- 
pressway and ramp volume for use in calculating ramp 
DHV's. 

AASHO Policy indicates that for urban areas, the DHV, or 
thirtieth highest hourly volume of the year, is the equivalent of 
the normal daily peak hourly volume. It has been the practice to 
vary the ratio of one-way to two-way traffic in such a way as 
to yield a continuity of the resulting values of DHV, as illustrated 
in Figure C-6 of AASHO Policy. (51 ' Thus the expressway DHV, on 
a section approaching an off-ramp, minus the off-ramp DHV equals 
expressway DHV beyond the off-ramp; this plus on-ramp DHV 
equals expressway DHV beyond the on-ramp, and so on, along the 
length of the expressway. This method, however, disregards two 
known factors. First, it is known that the peak hour does not occur 
at the same time either for all sections along the length of an ex- 
pressway, or on each ramp. This factor negates the validity of such 
arithmetic continuity. The time of occurrence of the peak volume, 
of course, has no bearing on the volumes for which the express- 
way sections and ramps must be designed, although it may affect 
detailed analyses of weaving movement. Secondly, it is also 
known, in general, that with symmetrical ramp design and in the 
absence of any adjacent large traffic generator with unusual 
hours of attendance, if a given ramp carries a certain volume in 
the A.M. peak period, the volume on the corresponding ramp in 
the opposite direction in the P.M. peak period will be closely 



INNER BELT AND EXPRESSWAY SYSTEM 



111-45 



ONE-WAY k FROM EMPIRICAL DATA ON EXISTING EXPRE S S WAYS 



fc 30 























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LEGEND 
















































RAMP 

A i 

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STATIONS 

V 

^ NORTHBOUND ON 

t NORTHBOUND OFF 
■ SOUTHBOUND ON 
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SSWAY STATIONS 

© NORTHBOUND 

A SOUTHBOUND 




















































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NOR T H E A S T 



EX PRESSWAY 



CENTRAL 



ARTERY 



SOUTHEAST 



EXPRESSWAY 



Exhibit T-32 



equivalent, unlike the example of Figure C-6 of AASHO Policy. 
Considering these factors, it was decided to investigate the 
DHV relationships mentioned above, with the purpose of basing 
DHV calculations on valid empirical data rather than attempting 
artificially to make the DHV volumes yield the customary continuity 
of values. This investigation was prompted by the suggestion, 
noted in AASHO Policy, 15 ' 1 as to the need for such research, as 
well as by the necessity of applying a rational and consistent 
method to arrive at a DHV from the assigned ADT volumes for 
each element of the Expressway System. 

EXPRESSWAY DESIGN HOUR VOLUMES 

The ADT capacity restrictions of the TISRO assignments, as 



noted in Section 3, were derived from projected values of K, D, 
and T judged appropriate for each portion of the Expressway 
System on the basis of evidence available from the Department 
regarding these values for existing expressways. With rational 
values of K assigned as described in Section 3, it was necessary 
only to reverse the computation to yield one-way DHV from the 
design ADT. On the basis that bidirectional equality of average 
daily traffic exists, it follows that the ratio k of one-way design 
hourly expressway volume to one-way ADT may be derived thus: 

Let v = directional design hourly volume, DDHV, 

V = two-way design hourly volume, DHV, 
D = ratio of DDHV to DHV, 



a = directional average daily traffic, DADT, 
A = two-way average daily traffic, ADT, 
k = ratio of DDHV to DADT, 
K = ratio of DHV to ADT. 

Then the two-way design hourly volume, V, is identically equal 
to the directional design hourly volume, v, divided by the ratio D: 



and 



V 

D 




V 


V 

KD 



111-46 



NNER BELT AND EXPRESSWAY SYSTEM 



But on the basis noted above, 



a = 



*A 



KD 



and thus 



2KD 



The directional DHV for each expressway segment is there- 
fore determined by multiplying the directional ADT by the value k, 
which is equal to 2KD. 

RAMP DESIGN HOUR VOLUMES 

For the purpose of determining the relationship of ramp 
DHV to ramp ADT, an investigation was made of existing express- 
way ramp usage. Field data regarding traffic volumes on exist- 
ing expressways and ramps were obtained from the Department. 
From this data, values for one-way ADT, directional peak-hour 
volume and directional counter-peak volume, as defined below, 
were calculated for each of the one hundred ramps in the exist- 
ing system (Northeast Expressway, Central Artery, and Southeast 
Expressway), including the interchange ramps of direct connectors. 
As expected, peak-hour flow did not occur at the same time for 
all parts of the system. Values of k were then found for each 
of the hourly flows, and a plot was made of expressway and 
ramp k against location, in order of geographic occurrence, for 
both A.M. and P.M. hourly volumes, as shown in Exhibit T-32. By 
inspection it was evident that a correlation existed between ex- 
pressway k and ramp k, as suggested by the trend lines of Ex- 
hibit T-32. Further examination of the field data yielded the con- 
clusion that the variations of traffic flow on both expressway and 
ramps were sufficiently wide-ranging that if the nature of the 
relationship could be determined, the results could be satisfac- 
torily applied to any combination of the expressway and ramp 
ADT's which had been assigned to the expressways of this Study. 
For further investigation the hourly data were divided into two 
primary categories depending upon type of ramp, and three sec- 



TABLE T-VII 

CORRELATING FACTORS DERIVED 

FOR RAMP-USE FUNCTION 



Ramp Type 


Flow Type 


Multiplier, * 


Exponent, n 


On 


Peak 


1.08 


0.009 


On 


Counterpeak 


3.46 


1.866 


On 


Diametral 


3.28 


1.876 


Off 


Peak 


1.49 


1.948 


Off 


Counterpeak 


1.95 


1.945 


Off 


Diametral 


5.40 


1.826 



ondary categories depending upon flow conditions, as follows: 

On-Ramps: Peak Flow, Counter-Peak Flow, and Diametral 
Flow. 

Off-Ramps: Peak Flow, Counter-Peak Flow, and Diametral 
Flow. 

Peak flow is defined as the maximum one-way hourly volume 
that occurs each morning and afternoon. Counter-peak flow is 
that which occurs in the opposite direction at the same time as 
peak flow. Diametral flow is defined as that peak flow which 
occurs in a section of a traffic facility where the volumes of the 
movement in each direction are essentially equal, or where the 
ratio, D, is equal to 50%. That part of the existing expressway 
system carrying diametral flow was found to be the Central Artery 
from Charlestown to its interchange with the Southeast Expressway. 

The problem then required determination of a functional re- 
lationship between the one-way ADT on that portion of the ex- 
pressway associated with a ramp, the ramp ADT, the peak or 
counter-peak expressway hourly volume, and the ramp peak hourly 
volume. Using the symbols previously noted, and the subscripts 
R for ramp and E for expressway, the relationship would take the 
form: 

VR = f (a R , a E , v E ) 




Rationally, as ramp ADT increases, the proportion of ADT 
in the peak hour decreases, or, the value of ramp one-way k 
varies inversely as the ramp ADT: 

a R 

It may also be reasoned that, as the proportion of express- 
way DADT occurring in the peak hour increases, the ramp hourly 
volume in that time period will also increase: 

v R ~ k E 

A further rationalization is that, as the ramp ADT increases, 
the ramp peak hourly volume will also increase: 

vr~ a R 

A logical combination of these dependencies was formulated: 



v R 



* 



V E 



a E a R 



in which the previous notations are used, and 

$ = a multiplying factor, 

n = an exponent, which might be negative, to account for 
the fact that a R enters these dependencies in different methods 
of variation. 

The field data was then used to determine those values of $ 
and n, for each of the categories, which would result in the great- 
est correlation between the left and right sides of the equation, 
by converting the equation to logarithmic form and applying the 
least-squares regression method. The computations were made 
on an IBM 709 electronic computer yielding values for $ and n 
as shown in Table T-VII. Graphs were then prepared for both 
on-ramps and off-ramps on the basis of these values, as shown 
in Exhibit T-33. 

These graphs are used by entering on the abscissa with the 
assigned ramp ADT (as shown in the Traffic Schematic Diagrams, 
Exhibits T-34 through T-39), reading upward to the curve for the 



NNER BELT AND EXPRESSWAY SYSTEM 



111-47 



associated expressway k (computed, as described previously, from 
the relevant K and D values shown in Exhibit T-28) and then read- 
ing left to the corresponding ramp k. As an example, as shown 
on Exhibit T-33 for an on-ramp ADT of 3000 vehicles per day, 
and a k of 7% on the adjacent expressway section, the ramp k 
would be 8.4%. The value of k R is then multiplied by the ramp 
ADT to arrive at the required ramp DHV. Thus, in the example, 
the ramp DHV would be 252 vehicles per hour. 

While it is recognized that the work involved in correlating 
the empirical data for preparation of these graphs by no means 
exhausts the possibilities for research on the relationships between 
ramp volumes and expressway volumes, it does result in a con- 
sistent, realistic approach to the determination of ramp design hour 
volumes for the purpose of this Study. These DHV values appear 
with the corresponding ADT volumes on the traffic schematic dia- 
grams and the Basic Design Exhibits. 



ASSIGNED TRAFFIC VOLUMES 

The traffic volumes determined by the procedures described 
above are for the design year 1975; however, the desire to use 
these expressway facilities is beyond the practical limits of design, 
and it is therefore anticipated that on most sections of the Express- 
way System the volumes indicated would occur now if the pro- 
posed facilities were in actual use. 

INNER BELT 

GENERAL 

Table T-VIII summarizes the relationship of design capacities 
to the TISRO and free assignments for the Inner Belt, the Central 
Artery, and the adjacent sections of the radial expressways. The 
assigned ADT volume on the section of the Inner Belt between 
the Southeast Expressway and the Southwest Expressway is signifi- 
cantly less than the recommended eight-lane design capacity, even 
though the free assignment desire is far greater. This condition 
is the result of the assignment of capacity volumes to those sec- 
tions of the Expressway System adjacent to this underloaded sec- 



DESIGN HOUR VOLUME FUNCTIONS 



EXPRESSWAY ON-RAMPS 



EXPRESSWAY OFF- RAMPS 




5 



/+ 




RATIO OF EXPRESSWAY DDHV TO EXPRESSWAY DADT, k F , % 




RATIO OF EXPRESSWAY DDHV TO EXPRESSWAY DADT, k £ , % 



10 15 20 

RAMP AOr, THOUSANDS 



25 



50 



tO 15 SO 

RAMP ADT, THOUSANDS 



25 



30 



Exhibit T-33 



tion, thus preventing more traffic from entering this section of the 
Inner Belt. Therefore, referring to the above Table, it will be 
noted that only 38% of the design capacity is assigned to this 
section, in which case the question arises as to the practicability of 
constructing eight lanes instead of the four lanes normally re- 
quired for the volumes shown. 

Under these circumstances, it must be considered that the 
conditions causing this sharp drop in volume in this particular sec- 
tion may be improved in the future by the introduction of other 
facilities such as: 

a. Improvements or separate facility to increase the capacity 
of the Central Artery. 

b, Improvements to increase the capacities of both the South- 
east and Southwest Expressways prior to their connection 
with the Inner Belt. 



c. Additional access ramps. 

d. Cross-town expressway between the Southwest and North- 
ern Expressways. 

Provisions should be made therefore in the design of this 
critical section to provide for these eventualities even though the 
presently-assigned volumes seemingly warrant only a four-lane 
facility initially. In addition, the desirability of planning for a con- 
tinuous eight-lane Inner Belt facility cannot be questioned. Ac- 
cordingly, the Basic Design Exhibits presented herein provide for 
this continuity of design and it is so recommended. 

RECOMMENDED LOCATION 

The volumes assigned to the Recommended Location, which 
follows the Ruggles Street alignment, are shown on Exhibit T-34. 
On Exhibits T-35, T-36, and T-37 are the volumes assigned to 



111-48 



INNER BELT AND EXPRESSWAY SYSTEM 




the direct-connector interchanges of the Recommended Location 
with the radial expressways. 

The 1975 assigned volumes reach capacity between the 
Charles River and Massachusetts Avenue, Cambridge. The 1975 
ADT assignments to the various sections of the Recommended Lo- 
cation are as follows: 

a. 67,000 vehicles per day: Southeast Expressway to South- 
west Expressway. 

b. 104,000 vehicles per day: Southwest Expressway to 
ramps in the Fenway area. 

c. 138,000 vehicles per day: Fenway area to connections 
to the Massachusetts Turnpike. 

d. 161,000 vehicles per day: Massachusetts Turnpike to 
ramps serving the Massachusetts Avenue area of Cam- 
bridge. 

e. 134,000 vehicles per day: Massachusetts Avenue, Cam- 
bridge, to Northwest Expressway. 

f. 130,000 vehicles per day: Northwest Expressway to 
Northern Expressway. 

g. 1 34,000 vehicles per day: Northern Expressway to Prison 
Point Bridge Interchange. 

h. 1 1 5,000 vehicles per day: Prison Point Bridge Interchange 
to present terminus of the Central Artery in Charlestown. 

Four lanes in each direction are recommended for the Inner 
Belt between direct-connector interchanges. The recommended 
lane balance at the direct-connector interchanges provides three 
lanes in each direction for the Inner Belt through-traffic and two 
lanes in each direction for the direct connectors to each radial 
expressway. 

Alternate Designs for parts of the Recommended Location 
occur at: 

a. The direct-connector interchange with the Southwest Ex- 
pressway. 

b. The vicinity of the Boston Museum of Fine Arts. 

c. The Charles River crossing. 

Traffic assignments for the Recommended Location and for 
the above Alternate Designs are shown on the Basic Design Ex- 
hibits; these assignments indicate the minor effects caused by varia- 



TABLE T-VIII 
INNER BELT TRAFFIC ASSIGNMENTS 



TISRO Average Daily Traffic 



Description 


From 


To 


No. of 
Lanes 


as % of 
Capacity 
Available 


as % of 
Free Assign- 
ment Desire 


Capacity 
as % of 
Free Assign- 
ment Desire 


Northeast Expressway 


* 


6 


100% 


48% 


48% 


Central Artery 


NE 


Tunnel 


6 


100% 


28% 


28% 


Sumner Tunnel 


* 


< 


4 


100% 


44% 


44% 


Central Artery 


Tunnel 


SE 


6 


100% 


30% 


30% 


Southeast Expressway 


* 


i 


6 


100% 


30% 


30% 


Inner Belt 


SB 


SW 


8 


38% 


23% 


61% 


Southwest Expressway 


i 


* 


8 


100% 


51% 


51% 


Inner Belt 


sw 


Tpke 


8 


69% 


45% 


65% 


Inner Belt 


Tpke 


NW 


8 


80% 


70% 


87% 


Northwest Expressway 


• 


k 


8 


97% 


67% 


69% 


Inner Belt 


NW 


N 


8 


78% 


58% 


74% 


Northern Expressway 


j 


¥ 


8 


100% 


57% 


57% 


Inner Belt 


N 


NE 


8 


90% 


48% 


53% 



* At interchange with the Inner Belt 

tions in the location of the local interchanges. However, each 
variation did produce changes in the volume assigned to individual 
ramps which in turn were considered in the design of these ramps. 
Assignments to Alternate Design I in the vicinity of the Museum 
of Fine Arts require a two-lane on-ramp, and to provide the proper 
lane balance, a northbound lane was added to the Inner Belt be- 
tween this ramp entrance and the Massachusetts Turnpike inter- 
change. 

ALTERNATE LOCATION 

The traffic assignments to the Alternate Location south of the 
Charles River along the Tremont Street route are shown on the 



Basic Design Exhibits. The volumes for this location are very similar 
to those shown for the Recommended Location. To provide ramp 
service comparable to the Recommended Location, northbound on- 
and off-ramps between the Massachusetts Turnpike and the South- 
west Expressway are closely spaced, due to the pattern of the 
existing arterial streets between the two locations. The traffic 
assignments to the Alternate Location north of the Charles River 
along the Grand Junction Branch of the New York Central Railroad 
are shown on the Basic Design Exhibits. Minor variations in the 
assigned volumes from those shown for the Recommended Location 
are apparent, and are due primarily to the differences in the ramp 
systems. 



INNER BELT AND EXPRESSWAY SYSTEM 



111-49 



NORTHWEST 

EXPRESSWAY 




Exhibit T-34 
DESIGN ASSIGNMENTS: INNER BELT 



MASS. TURNPIKE 

CONNECTIONS 



NORTHERN 
EXPRESSWAY 



SOUTHWEST 
EXPRESSWAY 



AVERAGE DAILY TRAFFIC 
DESIGN HOUR VOLUME 




111-50 



INNER BELT AND EXPRESSWAY SYSTEM 



POST, 



Op 



■ 'C 



6370 



3690 




66000 



5810 
SOUTHWEST 
EXPRESSWAY 



EXHIBIT T-35 

INTERCHANGE DESIGN ASSIGNMENTS 

INNER BELT AT SOUTHWEST EXPRESSWAY 




61090 
5380 



66950 
4S80 



EXHIBIT T-36 

INTERCHANGE DESIGN ASSIGNMENT 

INNER BELT AT NORTHWEST EXPRESSWAY 



NORTHERN 
EXPRESSWAY 




65240 



4760 



4 760 



EXHIBIT T-37 

INTERCHANGE DESIGN ASSIGNMENT 

INNER BELT AT NORTHERN EXPRESSWAY 



INNER BELT AND EXPRESSWAY SYSTEM 



111-51 



25125 



25125 



28120 



28120 



45620 



3710 




5000 



5000 



45620 
5470 

















* 


















-t 




































^ 
















4920 
520 \ 




54550 
Gf. f 5560 - 


1600 






K.- 




2820 


\ 


g 2060 


i *Y / 








K 




310 


7 1 


^J / 210 


/ ^^^< — 








<? 


50390 


/ 














. 4790 


/ 5 440 


u 










1830 
200 


\ 


u\ 


/ 




^Sj 


^\ 4920 


54550 \ 7^^- 
5560 / 

1600 






rj 




1 50390 


2820 / 
310 


\\ 


540 
2060 


ISO 








1830 


/ 1 




5440 




* 


2 20 






200 




\ 4 790 
530 






\ 









\ 690 
\ 




3320 






59540 


/ 350 






\ 5710 




A 9 7^0 
I \ 940 / 




^^^^■^^■^ 




6590 \ 


\ 


\ 3320 






690 


\ 59540 
5710 


360 


&>' 


9780 / 
910 

66000 
5810 

SEE EXHIBIT NO. T-35 



/ 5810 



975 



AVERAGE DAILY TRAFFIC 
DESIGN HOUR VOLUME 



Exhibit T-38 
DESIGN ASSIGNMENTS: SOUTHWEST EXPRESSWAY 



\ 



SOUTHWEST EXPRESSWAY 

RECOMMENDED LOCATION 

The ADT volumes assigned to the Recommended Location are 
shown on Exhibit T-38. The heaviest volume, 132,000 vehicles in 
1975, occurs just south of the interchange with the Inner Belt. 
The volumes decrease through the several interchanges to approxi- 
mately 91,000 vehicles just north of the interchange with Route 
128. However, the design hour volumes remain relatively constant, 



with only a minor reduction on the section between the Inner Belt 
and Route 128, due to the variable K, D, and T factors applied, 
as shown on Exhibit T-28. A minimum of four lanes in each direc- 
tion is recommended throughout the design section for the South- 
west Expressway. Extensive local improvements, including front- 
age roads, one-way streets and widening of local streets will be 
required at nearly all of the interchanges. A major part of the 
assigned expressway traffic originates south of Route 128. Of 
the total traffic assigned to the various interchanges between Route 



128 and the Inner Belt, approximately two-thirds have destinations 
northerly of the Inner Belt, with the remaining one-third destined 
southerly for Route 128 or beyond. Traffic volumes for all move- 
ments at the Route 128 interchange are shown on Exhibit T-38. 
The major movements at this interchange are the through move- 
ments on the Southwest Expressway, and the movements between 
the north and east, which are approximately equal. The movements 
between the north and east, of approximately 19,000 vehicles 
each, require two-lane direct connectors. 



111-52 



NNER BELT AND EXPRESSWAY SYSTEM 



V 



? U B L I C 



£4150 
£900 



ROUTE 3 
EXPRESSWAY 















27200 
3290 




27200 
3290 






2400 y 

320 N/ 
7700 X 
6?0 N/,^-^ 

3?. 500 <S^ 




44 50 
l/ 520 
X. 2500 

X/ soo 

N\ 22200 
\ y^ 2660 




16900 








24150 


2236 


1 2900 


16900 


2500 A. \ / J 




J ^\ 7700 
"^C 93 ° 


[24150 


2230 


29O0 




330 y XZ^ 






4450 / \ r^^i 
590 X J 

18850 / \. / 
2490 \ I 




^ \ 2400 
\ 320 
\ 25250 
To50~^ 






30550 \\ 
3700 \\ 


30550 

3700 







WflWn -^ 59890 — - 
5750 "^^^^^^^^^ 








10780 ^^^. ^# \\ 
l0?0 ^^C I li 




10160 ^^^ ^^\ II 

1000 ^1^ Jl 59270 




10760 ^^ \^^ JfJ| 5450 \ 

ceo ^i^^. /Ill ^r 




1A / l/l^^^^y 5450 
6865 ^^^1 Vy IM~~i ^^\ '0160 




4560 ^ 1 iV/l J ^~>^ ^r? 

480 Jrfl/l \jrJ^ 3915 

■ 11/ IX 60 ° 




8475 




If W \4560 

I f 490 

1 12465 




870 
12465 




1 1150 
1 1 8475 
1 93 ° 




1150 






ca **»o 4u e . J 








^3 II ^^ c OMCORO fl VE 




\\ FRESH POND PKY 





NORTHERN 
EXPRESSWAY 




BROAOWAY 



SEE EXHIBIT T-37- 



2 5840 
2940 



2510 
280 



800 



100 \ 



M->- 



ftlt 



27590 57000 
2980 



'1 



52740 \ 360 
\ 5270 \ 



52740 
\ 5270 

\ 22 20 



3180 

ROUTE 2 — 



\ 2040 
230 







% 

-£i3° NORTHWEST ^ 
9650 240 \ EXPRESSWAY — ■> 
930 —^^p^ ^ 1 

59270 /^r^\ J ^^ m *^"^^\ 
5450 ^J^^ \T """ eefl C JV . r 

^ \ V 19650 S7: 

r \ ^240 * 

59270\ "^. 

' ({> 

5450 

.,- — SEE INSET 


66790 
5880 

66 790 \ 
5860 

SEE EX 




• 2660 
290^ 


t> I lai ~— -. 
8100 "1 Ig 

83 ° \s\ 1* 

58760 JT if 923 ° 
\ 5880 / IjL--'"' 94 ° \ 

_*<A_ /Adl 5989 ° 
-x^^fc/VA / 5750 






(,/ 58760 VV 7^ 
5880 r**^ \ 
|?660 / 59890/ 
300 /9230 I 5750 

„,„„ 890/ 
BIOO 1 






HIQIT T-36— ' » 5 

w 




7B0 





1975 



AVERAGE DAILY TRAFFIC 



DESIGN 



HOUR VOLUME 



ALTERNATE LOCATION 



Exhibit T-39 
DESIGN ASSIGNMENTS: ROUTE 3, NORTHWEST & NORTHERN EXPRESSWAYS 

This expressway interchanges with Route 128, joins with the pro 



Traffic volumes assigned to the Alternate Location are essen- 
tially similar to those of the Recommended Location. Minor varia- 
tions occur south of the Cummins Highway interchange and these 
are due to the location of the next southerly interchange, which 
provides local service to a slightly different geographic area. From 
Cummins Highway northerly to the Inner Belt, the interchange loca- 



tions and the type of local service are basically the same as shown 
on the Recommended Location. 

ROUTE 3 AND NORTHWEST EXPRESSWAYS 

RECOMMENDED LOCATION 

The Recommended Location of the Route 3 Expressway and 
the Northwest Expressway are considered for assignment pur- 
poses as a single expressway from Route 128 to the Inner Belt. 



posed Route 2 Expressway at Appleton Street, Arlington, and 
interchanges with Alewife Brook and Fresh Pond Parkways, and 
with the Inner Belt. The 1975 ADT volumes for this expressway 
are shown on Exhibit T-39. Design hour volumes are approximately 
equal to capacity along the entire section from the junction with 
the proposed Route 2 Expressway to the Inner Belt. The ADT 
volumes vary from 114,000 vehicles after the junction with the 



INNER BELT AND EXPRESSWAY SYSTEM 



111-53 



Route 2 Expressway to 133,000 vehicles at the Inner Belt. Four 
lanes in each direction are recommended for this section of the 
Route 3 Expressway. 

From the Route 128 interchange to the junction with Route 2, 
the Route 3 Expressway volumes gradually increase from 48,000 
to 55,000 vehicles. Two lanes in each direction are recommended 
for this section. The volumes assigned to the interchange with 
Route 128 were analyzed and found to require a clover-leaf-type 
interchange as previously designed. At the two local interchanges 
between Route 128 and the junction of the Route 2 Expressway, the 
predominant movement is toward the Inner Belt, accounting for 
approximately seventy-five percent of all trips assigned to these 
local access points. 

After Route 3 joins with Route 2 at Appleton Street, Arling- 
ton, capacity volumes are predicted and local ramp assignments 
are therefore partially restricted. However, a continuous frontage 
road system is recommended from the junction of Route 3 and 
Route 2 to the existing Alewife Brook Parkway, which would serve 
local needs and provide additional arterial capacity for inter- 
mediate-length trips. 

A trumpet-type design is recommended at the interchange 
with the Alewife Brook Parkway. This design would provide ade- 
quate traffic service for Alewife Brook Parkway as it now exists. 
However, if Alewife Brook Parkway is to be reconstructed to ex- 
pressway standards, a directional-type interchange, as shown in 
the Basic Design Exhibits for the Alternate Location, should be 
provided. 

The weaving volumes and the limited weaving distance avail- 
able at the Concord Avenue-Fresh Pond Parkway interchange re- 
quire that the through movement to Fresh Pond Parkway be sep- 
arated from the local turning movements to Concord Avenue. The 
design recommended will adequately satisfy this condition and 
the local traffic needs. 

ALTERNATE LOCATION 

The Alternate Location for the Route 3 Expressway is sub- 
stantially different in concept from the Recommended Location, 
resulting in wide variances in the volumes assigned. The Alter- 



nate Location begins at the present terminus at Route 128 and con- 
tinues to a junction with the Northwest-Northern Connector. The 
ADT assignments to this section range from 56,000 vehicles at 
Route 128 to 77,000 vehicles at the junction with the Connector. 
Two lanes in each direction, with provisions for widening to three 
lanes from Route 128 to Ridge Street, Winchester, and three lanes 
in each direction from Ridge Street to the junction with the 
Northwest-Northern Connector, are recommended to accommodate 
the 1975 volumes. As part of this Alternate Location, Alewife 
Brook and Mystic Valley Parkways must be reconstructed to ex- 
pressway standards so as to provide a connection between the 
Northwest Expressway and the Northern Expressway. The ADT 
volume of traffic assigned to this Connector varies from 66,000 
vehicles to 78,000 vehicles, and requires three lanes in each 
direction. 

Directional-type interchanges are recommended at both the 
interchange of the Connector with Route 3 and with Route 2. 
The interchange of the Connector with the Northern Expressway, 
presently under construction, would require the addition of a ramp 
from the southbound lane of the Northern Expressway to the west- 
bound Connector to accommodate the assigned traffic. However, 
in recognition of the importance to local traffic desires of ramps 
under construction, and the great cost of providing the additional 
ramp, it would not be practical to recommend its inclusion in the 
basic design. 

The traffic assigned to the Alternate Location of the North- 
west Expressway, shown on the Basic Design Exhibits, is essentially 
the same as is shown for the Recommended Location. An eight- 
lane expressway, from the Inner Belt to the directional interchange 
with Route 2 and the Alewife Brook Parkway, is recommended. 

NORTHERN EXPRESSWAY 

RECOMMENDED LOCATION 

ADT traffic volumes assigned to the Recommended Location in 
1975 are shown on Exhibit T-39, and vary from 113,000 vehicles 
north of The Fellsway interchange to 123,000 vehicles at the 
Inner Belt. Eight lanes are therefore recommended. Complete 
local service is provided at The Fellsway interchange. Direct con- 



nections to the Sullivan Square viaduct, connecting to Rutherford 
Avenue, are provided to serve the Charlestown area, and also to 
relieve the Inner Belt between the Northern Expressway and the 
Northeast Expressway. 

ALTERNATE LOCATION 

The Alternate Location provides essentially the same traffic 
service; however, the local ramps at The Fellsway would not be 
able to handle the traffic as efficiently as the ramps provided by 
the Recommended Location. Traffic assignments are slightly higher 
due to the volume added by the connection of the Route 3 Ex- 
pressway to the Northern Expressway. The increase to 133,000 
vehicles would not change the number of lanes required. 







111-54 



NNER BELT AND EXPRESSWAY SYSTEM 





PART IV 



SOCIO-ECONOMIC ANALYSIS 



SECTION 1 - INTRODUCTION 



^osrg 



PO 



*L 



fc 



PURPOSE OF STUDY 

Planning a major limited-access expressway system in an 
urban area is a monumental undertaking. In past years, when 
highways traversed sparsely populated regions, the effects of 
the highway upon a community could be readily determined. 
The complex effects produced by the construction of urban ex- 
pressways require a prior determination of the immediate and 
deferred results on both the urban structure and its inhabitants 
in order that the orderly growth of the community may be stimu- 
lated and the social and economic welfare of its citizens pro- 
moted. The purpose of this socio-economic analysis is to assess 
the effects of alternative expressway locations on the communi- 
ties involved, and to suggest [what benefits might accrue follow- 
ing the construction of an expressway system. \ The expressways 
included in this Study are located in 13 communities. The Ex- 
pressway System, however, will affect many of the neighboring 
cities and towns. An area bordered by future Interstate Route 
495, therefore, has been used as the outer limit of the Socio- 
Economic Study Area. This area includes 121 separate municipal- 
ities, as shown in Exhibit S-l, and is referred to in the Socio- 
Economic Analysis as the Study Area. 

As indicated in the Third Progress Report of the Highway 
Cost Allocation Study, ". . . there exists a formidable array of 
direct and indirect benefits resulting from federal-aid highway 
improvement in addition to benefits resulting from actual use. 
Regardless of the label affixed to these kinds of benefits — 
whether they be identified as an extension of vehicular benefits, 
transferred benefits, or non-vehicular benefits — what seems sig- 
nificant is that there are real and extensive beneficiary groups 
other than highway users as such, that reap the advantages of 
highway improvements and that the total magnitude of these 
benefits is great." 141 * 

The approach devised for this Study included consideration 
of many elements not treated in detail by past studies. Such 

•References will be found in the Appendix. 

Exhibit S-l 
THE SOCIO-ECONOMIC STUDY AREA 




INNER BELT AND EXPRESSWAY SYSTEM 



IV-1 



factors as the overall economic base, the shifting population and 
the movement of people and goods by various modes of trans- 
portation, together with the factors of social characteristics, po- 
litical boundaries and family incomes were all considered in this 
analysis. As a result of this approach, emphasis was placed on 
selection of expressway locations that would provide maximum 
opportunity for the orderly social and economic growth and de- 
velopment of the cities and towns involved. The socio-economic 
analysis, considered together with the engineering determina- 
tions, served as the basis for recommendation of specific locations 
and their alternates. 

METHOD OF ANALYSIS 

The effects of the expressways studied were classified in 
two major groups: 

a. The analysis of the physical effects of the expressways 
as material entities newly introduced into an existing 
environment. 

b. The analysis of the functional effects of the expressways 
upon the long-range growth and development of the 
Study Area. 

The physical analysis is primarily, but not exclusively, an 
analysis of the short-run effects upon existing families, local munic- 
ipal governments, neighborhood groups, local merchants, and the 
other persons or institutions directly affected by placing an ex- 
pressway in a particular location. These effects are relatively 
simple to assess because they relate to tangible alterations in the 
spatial relationship in and around the expressways. Adjustments 
in the spatial relationships necessitated by construction, however, 
will influence the highway's effects in its functional role. The new 
pattern of land uses and land-use controls will act as limiting 
factors upon the changes engendered by altered time-distance 
relationships. The long-term effects of time-distance changes mani- 
fest themselves in many functional ways. 

The functional or long-range effects of the Inner Belt and Ex- 
pressway System will result from its ability to fulfill the travel needs 
of the Study Area in terms of altering the time-distance relation- 



ships between homes and offices, factories, shopping facilities, 
and recreation centers, and between areas of economic activity. 
Altered time-distances between areas of economic activity and 
their sources of supply and distribution will create opportunities 
for the relocation and the new location of economic activity. This 
new pattern of activity will be reflected in local government reve- 
nues and expenditures. 

The general principles upon which these analyses were based 
are those of contemporary systems analysis, in which the chain- 
like reactions among different sectors of the environment are 
analyzed to determine the effect of an alteration in one environ- 
mental factor upon the other components. The physical and func- 
tional effects influence different individuals and groups to varying 
degrees. For example, a loss of patronage to a merchant in one 
part of the Study Area will, generally, result in a gain to a mer- 
chant in another segment of the Study Area. To facilitate this 
Study, the affected persons and groups in each separate com- 
munity were identified and the nature of the effects upon them 
was carefully determined. Since the individually affected persons 
and groups are termed herein as "actors," this type of analysis 
is called an "actor analysis." Actors consist of local governments, 
residents displaced, community interest groups, commercial and 
business interests (business and consumer services, retail trade, 
real estate, and warehousing and truck terminals), manufacturers 
and public services. 

RELATIVE EFFECTS OF THE PHYSICAL 
AND FUNCTIONAL ANALYSES 

The actors remain the same in both the functional and physi- 
cal analyses, but the actual effects will be quite different. The 
local governments, for example, experience temporary loss in 
rotables, yet sufficient businesses and population can be expected 
to locate in the community following improved highway service to 
provide the community with compensatory resources. A particular 
change may have both positive and negative effects, if the actors 
affected are located in different areas; therefore, equal considera- 
tion was given to every actor to make certain that each was assured 



of maximum future benefits. In the final analysis, it was determined 
that the potential opportunities for urban growth and develop- 
ment, created in each of the several cities and towns affected by 
the Expressway System, would more than offset the temporary 
short-term losses, provided that intelligent, forceful efforts were 
made to realize the full potential offered by the improved ex- 
pressway service. The net benefits to the Study Area will be 
reflected in the greater efficiency of the urban structure as a 
place to live and work, resulting from the improvements to the 
area's transportation system. 

This Socio-Economic Analysis involves the prior determination 
of the net benefits for the Study Area. This determination, which 
includes a forecast of the social and economic conditions to be 
anticipated in the areas tributary to the Expressway System follow- 
ing construction, is one important consideration in the selection of 
the Recommended and Alternate Locations from among alternatives. 




IV-2 



NNER BELT AND EXPRESSWAY SYSTEM 



SECTION 2 - POPULATION AND EMPLOYMENT PROJECTIONS 






o 



& 



L 



*ft 



GENERAL 

^ One of the first problems of assessing the functional effects 
of the Expressway System was to estimate the probable magni- 
tudes and distributions of the future population and employment 
that would occur in the Study Area if the expressways are not 
constructed. This set of projections served as a basis for com- 
parison with estimates based upon construction of the Express- 
way System. It is recognized that there may be some cross move- 
ment in the locations of both people and jobs in the fringes of 
this area. However, it is expected that these will be proportion- 
ately small when compared to the total activity involved. 

A thorough study of the basic economic activity in the area, 
together with projections of future potentials, were made through 
detailed analysis of the forces that influence employment. Em- 
ployment trends were analyzed in sufficient separate components 
to observe the growth, decline, and shifting locations of the more 
important industries within the Study Area. Employment statistical 
data was collected and analyzed on the basis of non-manufactur- 
ing and manufacturing categories using the Standard Industrial 
Classifications supplied by the Massachusetts Department of Labor 
and Industries. The employment estimates provided an important 
basis for the population projection. When the employment pro- 
jections were completed, related population estimates were ob- 
tained by converting employment into total population. The esti- 
mates of population, based on employment, were then checked 
against simple apportionment and linear extrapolation techniques. 
Both the population and employment values were then converted 
into spatial requirements of future developments by assuming an 
average density of development for each class of activity and for 
each city and town in the Study Area. The effects of these future 
developments will be reflected in the individual community's serv- 
ice costs and revenues. Recognition was given to possible future 
changes in zoning ordinances and subdivision regulations and prob- 
able future changes in these were estimated through interviews 
with officials of the various communities. 



METHODOLOGY FOR POPULATION 
AND EMPLOYMENT PROJECTIONS 

Projections of population and employment for 1975 were 
developed for the Socio-Economic Analysis and to provide basic 
data for use in the traffic generation and assignment procedures 
outlined in the Traffic Analysis Section. General population pro- 
jections for the Study Area were available, but were adjusted 
as noted herein to conform to the requirements of this analysis. 
Employment projections for the Study Area were non-existent, 
and these estimates had to be made independently. 

A comprehensive forecast of population and its distribution 
for Greater Boston, through 1970, was made available by the 
Greater Boston Economic Study Committee. (8) Two adjustments 
were made to this information; first, the control total was adjusted 
so that the new figure would include only those communities in 
this Study Area; and second, from this new control total, an ex- 
trapolation was made from 1970 to 1975, to arrive at the pre- 
dicted 1975 population control total of 3,600,000 for the Study 
Area. This population was then redistributed to the communities 
in the Study Area. Since these distributions did not account for 
changes in regional transportation, they served as the basis for 
comparison with distributions based upon construction of the Ex- 
pressway System. 

After the employment projections were completed, an inde- 
pendent population estimate was made by converting the em- 
ployment estimates into total population. This projection, using the 
results of both low and high economic estimates, ranges between 
3,300,000 and 3,900,000 people. The median of these extremes 
checks with the population control total of 3,600,000. However, 
since the individual city and town estimates obtained from the 
employment predictions take into account not only the extrapo- 
lation of existing growth patterns but also the effects of the con- 
struction of the Expressway System, they differ considerably from 
those forecast by the Greater Boston Economic Study Committee. 

The employment, estimates for 1975 are based on a recon- 
ciliation of the results of three separate projections: 
a. Apportionment Forecasts. 



b. Projection of Local Trends. 

c. Production Workers Forecast. 

The estimates by apportionment were made by projecting 
to 1975 the changing proportion of local to national employment, 
for maior non-manufacturing and manufacturing categories, using 
statistics supplied by the Massachusetts Division of Employment 
Security and comparable national projections. IM 

Another method of obtaining control totals for employment 
in the Study Area involved extrapolation of past employment 
trends of major non-manufacturing and manufacturing categories. 
The employment statistics reported by the Division of Employment 
Security represent approximately 80% of the total employment 
in the Study Area. Government workers, self-employed profes- 
sionals, entrepreneurs and employees of non-profit institutions are 
not included in these statistics. With the assistance of the U. S. 
Department of Labor and the Massachusetts Division of Employ- 
ment Security, estimates were made of those employees not in- 
cluded, in order to determine the total employment in the Study 
Area. Past employment in each category was extrapolated to 
1975 and the several totals were aggregated to give the second 
trial' employment control total. 

Projections of production workers for Standard Industrial 
Classifications were made on the assumption that the future dis- 
tributions of production workers would be related to the total 
industrial employment figures prepared by the Division of Em- 
ployment Security. For this purpose, the Massachusetts Depart- 
ment of Labor and Industries made available statistics, by town 
and by manufacturing classification, of the number of production 
workers, value of stock and equipment, value of output, wages of 
production workers, and number of establishments. These statistics 
cover only those firms actually producing within the Commonwealth, 
and provide a rich source of comparable data on manufacturing 
activity in Massachusetts. However, since the Department of Labor 
and Industries collects its data in a manner which is different from 
that of the Division of Employment Security, these data had to be 
regrouped according to the Standard Industrial Classification Sys- 
tem before they could be collated with data obtained from the 
Division of Employment Security. 



INNER BELT AND EXPRESSWAY SYSTEM 



IV-3 



The Massachusetts Division of Employment Security collects 
its employment statistics on the basis of U. S. Census Standard 
Industrial Classifications, and reports total employment in manu- 
facturing categories, regardless of whether the actual production 
is carried on at the particular location, i.e., a regional sales office 
of a national firm, which manufactures its product elsewhere, 
would be classified under the appropriate manufacturing category, 
and the firm's total employment listed. These statistics, therefore, 
report greater numbers of persons in manufacturing categories 
than would be anticipated by the ratios of production to total 
workers, reported in the U. S. Census of Manufacturers. 

The data by the Massachusetts Department of Labor and 
Industries, which incorporates the implicit local rate of techno- 
logical innovation, was used in the final forecast of production 
workers, primarily because projections of productivity and value 
added could be made for employment groups representing the 
actual manufacturing employment within Massachusetts. In addi- 
tion, this data would be free of the biases which the estimates 
by apportionment and by projection of local trends may have 
inherited from using the statistics supplied by the Division of Em- 
ployment Security. Furthermore, the projected series could be 
aggregated into classifications comparable with the estimates by 
apportionment and projection of local trends. 

To make the projections of production workers, the past 
productivity and value added were put in terms of constant dollars. 
The productivity and value added were then extrapolated to 1975. 
From these extrapolations, the number of production workers was 
computed as the ratio of value added to productivity, and then 
expanded to total manufacturing employment using ratios of 
production to total workers, obtained from the U. S. Census of 
Manufacturers. 



Exhibit S-2 
VACANT BUILDABLE LAND ZONED RESIDENTIAL 




IV-4 



NNER BELT AND EXPRESSWAY SYSTEM 



BO: 



% 



£*4RY 




ECONOMIC ASSUMPTIONS FOR 
EMPLOYMENT PROJECTIONS 

Each of the three methods used for forecasting the employ- 
ment control total for the Study Area involved assumptions and 
investigations made of the existing distribution and trend of each 
industry in the Study Area and the national trend of industries. 
These governing assumptions and investigations concerned national 
projections, regional assumptions influencing local forecasts, ap- 
portionment forecasts, employment extrapolations for major non- 
manufacturing categories and manufacturing categories, and 
employment projections and distributions of manufacturing cate- 
gories. 

National projections were made for twenty-six employment 
categories to permit an apportionment forecast of local economic 
activity. To measure national activity through 1975, a projection 
by Dr. Ernst Jurkat' 61 was used. The assumptions on which these 
projections were based were verified by comparison with a series 
of forecasts made by the National Planning Association. (7( 

The regional assumptions influencing local forecasts were 
formulated after investigation of growth patterns, interviews with 
public and private agencies, and review of studies on manufac- 
turing trends in the area made by Frank W. Gery (3) and Roger 
Johnson. 151 

Fundamentally, the apportionment forecast related trends in 
employment in the region directly to comparable national em- 
ployment trends. The changing relationship was separately fore- 
cast between the number of local jobs available within a particular 
industry and the number of jobs available on the national scene. 
With minor modifications, however, the number of jobs available 
in the local area were assumed to fluctuate directly with national 
trends. 

Extrapolations of local employment were made for non- 
manufacturing and manufacturing categories, based on past em- 
ployment statistics furnished by the Massachusetts Division of 



Exhibit S-3 
VACANT BUILDABLE LAND ZONED COMMERCIAL 



INNER BELT AND EXPRESSWAY SYSTEM 



IV-5 



Employment Security, analyses of national and local influences, and 
on special studies for certain key industries, such as the leather, 
shoe, textile, and electrical machinery (including electronics) in- 
dustries. 

Projections and distributions of major manufacturing activities 
in the Study Area were made on the basis of data supplied by 
the Massachusetts Department of Labor and Industries and on the 
basis of analyses of the past employment and future potential of 
forty-four manufacturing activities within the Study Area. The 
trends of these activities were analyzed from this data because 
it was the only data available which supplied information specifi- 
cally for regional productivity and output. This comprehensive 
data was preferred because it contained information on actual 
manufacturing activities in Massachusetts. 

Generally, the inlying areas will benefit from the construc- 
tion of the Expressway System, particularly in those industries em- 
ploying large numbers of unskilled and semi-skilled workers which 
do not have large investments in plant and equipment. Further- 
more, because of comprehensive redevelopment programs in the 
inlying areas, growth will be quite sizable, including the estab- 
lishment of some large new plants. The outlying areas, particularly 
at the junctions of the radial expressways with the circumferential 
expressways, Route 128 and Interstate Route 495, will experience 
considerable increase in the establishment of new plants relying 
upon skilled and professional employees, and requiring a consider- 
able investment in plant and equipment. 

METHODOLOGY FOR DISTRIBUTION OF 
PROJECTED POPULATION AND EMPLOYMENT 

Two general approaches, the manual distribution approach 
and the gravity model approach, were employed for the distri- 
bution of projected employment and population. The manual dis- 
tribution approach compares industrial locational needs with the 
land available for building throughout the Study Area. The gravity 



Exhibit S-4 
VACANT BUILOABLE LAND ZONED INDUSTRIAL 




IV-6 



INNER BELT AND EXPRESSWAY SYSTEM 







PERSONS PER TOTAL 
BU1LDABLE ACRE 



model approach assumes that the future location of population 
and employment will alter with changes in the time-distance re- 
lationships between population centers within the Metropolitan 
Area. For example, as its time-distance from the core area changes 
in the future, a community will assume characteristics similar to 
those cities or towns along the same sector presently having that 
time-distance. The results of each method were compared and 
reconciled to provide estimates for each of the 121 cities and 
towns in the area and then aggregated and checked against the 
control totals developed for the Study Area. 

The basic data collected for the distribution process in- 
cluded complete itemized land-use data, differentiated by type, 
by zoning classification, and by the development potential of 
vacant land. For the inlying densely settled cities and towns, a 
study was made of urban renewal projects and the probable 
future re-use of land scheduled for clearance. Several factors 
investigated were considered to influence the distribution of future 
population and employment: the land-use patterns and plans of 
each community, the zoning of available land suitable for build- 
ing as shown on Exhibits S-2, S-3, and S-4, local utility coverage, 
local tax rate and assessment policies, the skills of local residents, 
the proximity to and quality of local modes of transportation, 
trends in new plant construction, locational needs of different 
industries, sites currently offered for sale by industrial realtors, 
trends in housing construction, and population density as shown 
on Exhibit S-5. It was assumed that inundated areas or vacant 
land with slopes in excess of 25% would not be developed by 
1975, and that marshland and land with slopes of 1 5 to 25 per- 
cent would be developed only if the demand is high. 

Four separate employment and population distributions were 
made by both the gravity model and the manual distribution, or 
distribution-by-inspection, techniques, assuming: 

a. No further expressway construction with a medium level 
of economic activity. 



Exhibit S-5 
POPULATION DENSITIES 



NNER BELT AND EXPRESSWAY SYSTEM 




IV-7 



b. Construction of the Expressway System with a low level 
of economic activity. 

c. Construction of the Expressway System with a medium 
level of economic activity. 

d. Construction of the Expressway System with a high level 
of economic activity. 

The distributions which assumed no further expressway con- 
struction were simply extrapolations of existing land-use patterns 
for each community. While this method takes into account the 
past rate of transportation change, because it does not account 
for the new rate of change implicit in the construction of the 
expressways, it serves as a basis for comparison with those esti- 
mates based upon completion of this Expressway System. 

The manual distribution approach employs the concept of 
location theory. It requires a detailed knowledge of the locational 
requirements of each separate industry and a map showing not 
only the available sites, but also their particular characteristics. 
Manual distribution estimates of future population and employ- 
ment were made by plotting employment statistics on maps show- 
ing the regional distribution for each of the 56 separate 
employment categories, and by analyzing the needs and patterns 
of existing industry in the area as well as the particular environment 
of each community. 

After locating future industrial employment, the distribution 
of population was accomplished by utilizing "journey-to-work" 
theory. This theory utilizes the observed time-distance relationship 
between homes and jobs in terms of the length of time people 
are willing to travel to their place of work. This information, which 
varies from city to city, was represented by a map showing travel 
times surrounding particular industrial concentrations. Then, utiliz- 
ing the probable incomes of employees within that industrial con- 
centration, future population was distributed among the existing 
and potential housing within areas having the proper travel-time 
relationship. When the residential locations of industrial workers 



Exhibit S-6 
RINGS AND SECTORS OF THE STUDY AREA 




1V-8 



NNER BELT AND EXPRESSWAY SYSTEM 





f TOPSFIELD .-Q 



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VERTICAL SCALE 
TOTAL POPULATION 



POPULATION LEGEND 



were established, residential service activities and their employ- 
ment were also located. The added employment of these service 
activities, such as retail trade, service industries, institutions, gov- 
ernment and governmental enterprises, also had to be distributed 
to residential locations on the basis of the "journey-to-work" theory. 

The basic assumption of the gravity model technique as used 
in socio-economic analyses is that the characteristics and degree 
of development are a function of time-distance between the com- 
munities. Time-distance serves as the independent variable upon 
which the variables of population and employment depend. A 
gravity model has the advantage of being simple, quick, and ob- 
jective, but has the disadvantage of placing a heavy reliance upon 
the single variable of time-distance. Use of time-distance as the 
independent variable assumes that the other influences on future 
distributions, such as the willingness of people to travel, the avail- 
ability of space, and fluctuations in the real estate market, are 
fixed while in reality they vary independently of time-distance. 
Therefore, the results of a gravity model analysis must be care- 
fully examined and possibly modified, using carefully weighed 
judgment. 

The basic application of a gravity model to socio-economic 
distributions is usually suitable only where there is a single politi- 
cal jurisdiction and where the individual cities or towns do not 
employ defensive zoning restrictions which may hamper the normal 
pattern of development. Since this Study Area is comprised of 1 21 
independent cities and towns, each having its own zoning regula- 
tions which could restrict future development, and the relative size 
of Boston and its influence over the entire area were not considered 
predominant, a gravity model technique was employed in this 
analysis which assumed a restricted future development of vacant 
buildable land in outlying cities and towns in accordance with exist- 
ing and proposed zoning regulations. This technique also employed 
a "Relative Attraction" factor to incorporate the aggregated effects 



Exhibit S-7 
POPULATION DATA 



INNER BELT AND EXPRESSWAY SYSTEM 



IV-9 



on each city and town in the Study Area, from both Boston and 
its regional subcenters. This factor relates the attractiveness of a 
community for new development to the attractions of surrounding 
centers, as a function of their respective populations, relative 
travel times, and relative change in travel times. The relative in- 
fluences of Boston, Lynn, Lawrence, Lowell, Worcester, Brockton 
and Providence were considered in this analysis. 

In the gravity model technique, the Study Area was divided 
into rings and sectors which circumscribed and grouped areas 
having similar characteristics, as shown on Exhibit S-6. Popula- 
tion and employment densities in each of these areas were com- 
puted and plotted on distribution curves related to time-distance 
from downtown Boston. The estimate of the amount of vacant, 
buildable land to be developed by 1975 was guided by the 
application of the gravity model together with study, by inter- 
viewing local officials and businessmen, of the relative willing- 
ness of a community to accept development. The amount of land 
to be developed was then converted to population, using weighted 
densities within the zoning provisions, and to employment, using 
densities of recent development. 

The results of this method were contrasted with the other 
estimates outlined above, to arrive at the best possible compara 
tive estimates. In the reconciliation of the gravity model and the 
manual distribution estimates, special consideration was given to 
saturation magnitudes, or maximum potential population, under 
present zoning regulations. It was considered that the gravity 
model analysis would provide the skeletal structure of future em- 
ployment and population distributions, and that careful recon- 
ciliation, based upon locational theory, and an examination of 
past trends would yield reasonable results. The population and 
employment data for past years and the 1975 projections are 
shown on Exhibits S-7 and S-8. 



Exhibit S-8 
EMPLOYMENT DATA 




\ ( V NAT.CK \U NEEDH AM AnR r^-J^ ^ J\\ &- 

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VERTICAL SCALE 
TOTAL NUMBER OF PERSONS EMPLOYED 

EMPLOYMENT LEGEND 



IV-IO 



INNER BELT AND EXPRESSWAY SYSTEM 



SECTION 3 -ACTOR ANALYSIS OF THE FUNCTIONAL EFFECTS 



BO^: 



GENERAL 

Expressway construction of the magnitude contemplated in 
this Study will produce fundamental changes in the structure of 
the Study Area by altering time-distance relationships among 
the cities and towns which comprise this area. These alterations 
will inevitably result in concomitant changes in the locations of 
future residential and industrial development. The subject of this 
analysis is the effect the altered patterns in the regional develop- 
ment will have upon the various actors previously identified. A 
general discussion of the functional effects on these actors is pre- 
sented here. 

LOCAL GOVERNMENT 

The altered rate of residential and industrial development 
experienced by each community will affect the community's future 
revenues and service costs. If the development rate is reduced, 
then the community will not only have a lesser growth of tax- 
producing properties but also lower service costs associated with 
community development. On the other hand, if the rate of de- 
velopment is increased, the community will obtain increased reve- 
nues from taxable properties and be faced with the additional 
costs associated with such growth. Although local governments 
will experience a temporary loss of rotables, increased accessi- 
bility provided by construction of the Expressway System will stim- 
ulate the development of new industrial and residential activities, 
thereby actually strengthening the communities' tax bases. Future 
growth and development in a community, however, is not predi- 
cated upon construction of the expressways alone. New transpor- 
tation facilities offer a potential for improvement that must be 
integrated with other elements of the communities' future planning 
in order to obtain the maximum benefits afforded by construc- 
tion of the Expressway System. Generally, construction of the 
system will accelerate the industrial and residential development 
of suburban communities. These communities should plan to direct 
this additional growth through suitable land use controls, in order 
to maintain a favorable balance between community service costs 
and revenues. 

The effects of construction of the Expressway System on 



the more densely settled inlying areas will be quite different be- 
cause of the limited supply of vacant, buildable land within these 
communities. The proposed network of expressways will ease 
local street congestion in these inlying areas, thus speeding the 
movement of people and goods into and out of the core area. 
In order for these inlying communities to realize their full poten- 
tial for future industrial activities, suitably located and compet- 
itively priced and designed sites must be provided. Interviews 
with public officials of these communities indicate that they in- 
tend to relate their urban renewal activities closely to the express- 
way construction, thereby capitalizing on the potential for new 
development afforded by the Expressway System. 

COMMUNITY INTEREST GROUPS 

Construction of the Expressway System will broaden the scope 
of the numerous cultural, educational, religious and recreational 
activities presently located within the Study Area. New activities 
may also be located at the focal points of the Expressway System, 
where they will be directly accessible to all sections of the Study 
Area. Increased accessibility afforded by construction of the sys- 
tem will encourage increased attendance. 

COMMERCE AND BUSINESS 

BUSINESS AND CONSUMER SERVICES 

Construction of the Expressway System will increase the 
accessibility of business and consumer services to both the labor 
pool and the patrons of these establishments. The overall de- 
velopment of industrial and residential activities, in communities 
where these services are located, will further stimulate the de- 
velopment of other commercial activities surrounding the facilities. 

RETAIL TRADE 

Accessibility afforded by construction of the Expressway Sys- 
tem will expand the influence of the present trade areas thereby 
enhancing the status of retail trade. Opportunities generated be- 
cause of expressway construction will stimulate the development 
of new commercial centers and contribute to modernization of 
existing facilities. 



REAL ESTATE 

The effect on real property values of altered time-distance 
relationships will benefit both the property owners and the real- 
tors managing industrial and residential transactions. In general, 
real estate values will increase in all areas because of the im- 
proved time-distance relationship to the downtown area. Increases 
will be most notable at the intersections of radial expressways 
with circumferential expressways such as the Inner Belt, Route 128 
and Interstate Route 495. It is anticipated that the increase in 
property values will follow the observed pattern reported in other 
economic analyses. 14 ' These analyses indicate that there will be 
a significant increase in real estate values adjacent to the Express- 
way System during the years after its construction, followed by 
a gradual stabilization as the pattern of traffic movement be- 
comes established. 

WAREHOUSING AND TRUCKING ACTIVITIES 

Generally, the location of warehouses and truck terminals 
will depend upon the future distribution of manufacturing activi- 
ties which, in turn, are dependent upon the improved time-distance 
relationship among the communities in the Study Area following 
completion of the Expressway System. If the locations of manu- 
facturing activities are radically altered, the distribution of ware- 
housing and trucking activities will be adjusted so they may con- 
tinue to serve economically their major functions. 

MANUFACTURING ACTIVITIES 

The alteration of transportation patterns will significantly af- 
fect those industries where transportation costs constitute a major 
portion of their operating costs. If transportation improvements 
will enable these industries to reduce their operating costs, then 
they may locate in order to realize these savings. Another factor 
that will affect the location of manufacturing activities is the future 
distribution of the labor pool. If certain components of the labor 
pool are located in a particular area because of increased acces- 
sibility afforded by construction of the Expressway System, in- 
dustries dependent upon this labor may also locate to take ad- 
vantage of the labor pool. In either case, their total costs will be 
lowered considerably owing to increased accessibility, thereby per- 



INNER BELT AND EXPRESSWAY SYSTEM 



IV-1 1 



miffing them to compete more effectively in the regional and 
national markets. Their successful participation in these markets 
will enhance the economic strength of the region. 

PUBLIC SERVICES 

The future dispersion of population and economic activity 



throughout the Study Area, and the development of municipalities 
at low population densities, together with an increasingly higher 
standard of living, will create new demands for improved educa- 
tional facilities, public health and medical services, police and fire 
protection and other public service facilities. Modern transporta- 



tion facilities will increase the scope and area of influence of 
these services and permit further improvements, efficiencies and 
enlarged service areas. Since many of these services regularly 
rely on motor-vehicle transportation for effective operation, con- 
struction of the Expressway System will have a beneficial effect 
on the many public services which are vital to modern living. 




IV-12 



INNER BELT AND EXPRESSWAY SYSTEM 



SECTION 4 - ACTOR ANALYSIS OF THE PHYSICAL EFFECTS 



GENERAL 

The research method for the actor analysis of the physical 
effects required compilation of basic information to verify the 
effects of expressway construction upon the various actors pre- 
viously identified. Comprehensive surveys were undertaken in 
order to obtain the background data necessary for determining 
these effects. Interviews were conducted with city and town offi- 
cials for each of the 121 communities in the Study Area. Infor- 
mation was obtained on population and demography, town fi- 
nances, subdivision and zoning regulations, utility coverage, rail 
and bus transportation service, major employment centers, tax- 
exempt parcels, and future plans for urban renewal and new de- 
velopment. With the cooperation of the Greater Boston Economic 
Study Committee, land-use and zoning studies were undertaken 
throughout the Study Area, except for a few inlying cities and 
towns where this information was readily available. Detailed field 
surveys were undertaken along the expressway corridor loca- 
tions to obtain information for each individual parcel, pertaining 
to its use, the age and condition of the structure, number of 
dwelling units, number of off-street parking spaces, and the name, 
location and type of non-residential activity. 

To supplement the above, a series of additional interviews 
were undertaken with realtors and leaders of community interest 
groups within the corridors of the expressway locations. From 
these interviews, information was obtained on future plans for 
expansion and development, the manner in which public and 
private facilities would be affected, actual prices of recent prop- 
erty sales, and the income and rent characteristics of households 
in the corridors of expressway location. 

A detailed survey of property values was undertaken by 
analysis of recent real estate transactions (l) , which permitted 
estimates to be made of the ratios of assessments to fair market 
values within the various expressway corridor locations. This in- 
formation served to permit an understanding of the kinds of 
properties located in these corridors and to provide a basis for 
preparing the right-of-way cost estimates. 

A general discussion of the physical effects on the various 
actors is presented here. 



LOCAL GOVERNMENT 

^ The local governments will benefit from slum clearance by 
condemnation of blighted areas for expressway rights-of-way; 
thus construction of the Expressway System can implement plans 
for renewal and redevelopment. In many instances, the division 
of land uses is facilitated when the expressway location sepa- 
rates industrial areas from declining but salvageable residential 
communities. 

The acquisition of taxable properties for construction of the 
system will cause some temporary loss in revenue to the local 
government. However, new commercial and industrial develop- 
ments locating in the area due to the proximity of the Expressway 
System will strengthen the communities' tax bases. 

RESIDENTS DISPLACED 

Residents of property acquired for construction of the Ex- 
pressway System will incur moving costs, and unless located in 
a renewal area, which would make them eligible for relocation 
assistance, low-income families may experience some hardship. 
A program coordinated with urban renewal activities, involving 
joint agency assistance for aid in relocation of those displaced 
by expressway or urban renewal construction, should be considered. 
This program, together with coordinated construction scheduling, 
would permit adequate facilities to be made available under re- 
newal construction programming in anticipation of displacements 
that will be necessary for expressway construction. 

COMMUNITY INTEREST GROUPS 

Community interest groups will be affected by the future 

distribution of population and employment. Some social clubs, 
churches, and other non-profit institutions may experience a de- 
cline in membership while other new organizations will be estab- 
lished in rapidly developing communities. 

COMMERCE AND BUSINESS 

BUSINESS AND CONSUMER SERVICES 

Construction of the Expressway System will generally cause 
the demand for business and consumer services to increase. Those 



affected by construction of the system may experience temporary 
short-term effects that will be more than counterbalanced by re- 
newed activities undertaken in response to increased demand. 
The presence of the expressways will generally increase the values 
of these activities, because of an expanded area of influence 
created by increased accessibility. 

RETAIL TRADE 

The major effect of construction of the Expressway System 
upon retail trade will be a modification of the trade areas sur- 
rounding the sales outlets. Usually the loss in trade area for 
one retailer will mean a gain in trade area for another. Re- 
tailers will benefit from the proximity of the Expressway System 
to their establishments through sight-advertising advantages simi- 
lar to those presently provided along Route 128. 

REAL ESTATE 

The effect of the Expressway System will be favorable for 
commercial or industrial real estate as well as for residential 
property. Recent analyses conducted after completion of various 
expressways indicate that neighboring residents generally regard 
highways as conveniences. (4) 

On Route 128, more than $175,000,000 worth of buildings 
employing over 28,000 workers have been built; in June, 1955, 
there were 39 companies in operation and 14 additional under 
construction. (2) Since 1955, many of these plants have been com- 
pleted and still many more are now under construction. 

WAREHOUSING, TRUCK TERMINALS AND MANUFACTURERS 

The general effect upon these activities includes increased 
accessibility to both the labor pool and consumers, sight-advertis- 
ing advantages, and potential for physical expansion as listed 
above for the other commerce and business activities. 

PUBLIC SERVICES 

Various public services may experience the effect of having 
to relocate some existing facilities as a result of construction of 
the Expressway System. 



INNER BELT AND EXPRESSWAY SYSTEM 



IV-13 



SECTION 5 -ACTOR ANALYSIS BY COMMUNITY 



INTRODUCTION 

All communities in the Study Area will benefit to varying 
degrees as a result of the construction of the Inner Belt and 
Expressway System. Construction of the System will change the 
form of this Area. New land-use controls should be adopted by 
local governments to obtain maximum advantage from the changes 
engendered by the altered time-distance relationships effected 
for the 121 cities and towns. Redevelopment plans of local com- 
munities, together with plans for private developments, will inevi- 
tably be changed to be compatible with and to take advantage 
of expressway construction. These new programs will have a 
significant effect on future economic activity in all the commu- 
nities. 

Analysis of the functional effects provided an understand- 
ing of the magnitude of long-range opportunities for growth and 
development which could be realized if local programs are co- 
ordinated with expressway construction. The functional effects 
must be considered in establishing a priority schedule for the 
expressway construction. The functional analysis was used to 
predict the probable future effects of expressways on the distri- 
butions of population and employment. 

These forecasts of population and employment in the year 
1975, both with and without the Expressway System, are based 
on the reconciliation of data for which a wide range of interpre- 
tation is practicable. A small modification in the assumptions 
will inevitably lead to significant variations in the forecasts. The 
quantitative forecasts, therefore, while useful, are intended to 
indicate pronounced relative trends and it is these relative trends 
which are of primary importance. 

To relate construction programming to population and em- 
ployment distribution involves a process of successive approxi- 
mations. A construction program is first assumed from traffic 
patterns based on population and employment distributions, as- 
suming all expressways will be built concurrently. The resulting 
traffic movements implicit in the assumed program will, in turn, 
affect the distributions and may suggest changes in the initial 
priorities assigned. This reciprocal process may be continued 



until the recommended priorities develop optimum practicable 
loadings on all portions of the Expressway System. 

In order to determine the effect of construction priorities on 
the distributions of population and employment for this Study, a 
correlation was made between past highway construction and 
community growth. This correlation showed that there is a time 
lag ranging from four to eight years after the completion of 
highway improvements before the area development rate returns 
to normal and the full net effects precipitated by highway con- 
struction can be assessed. Since the construction period for all 
expressways included in this Study is within this time range, ad- 
ditional population and employment distributions were not con- 
sidered to have a significant effect on assignment of construction 
priorities. 

The studies estimated the changed locations of future resi- 
dential and industrial development within the entire 121 cities 
and towns and the effects of these changes were analyzed in 
terms of the various actors for the 13 cities and towns through 
which the expressways will pass. A summary of this analysis for 
each is presented here. 



ARLINGTON 

The present population and employment in Arlington are 
approximately 50,000 and 4,700 respectively. The trend in the 
past decade has been an increasing rate of growth, and this 
trend is expected to continue. Without expressway construction, 
Arlington will have a population of 54,600 and employment op- 
portunities for 5,500 in 1975. With the construction of the Ex- 
pressway System the population will increase to approximately 
55,800, and employment opportunities will increase to 6,500. 
More than 250 additional residential acres will be developed in 
Arlington by 1975, of which only 50 acres are attributable to 
expressway construction. The remaining acreage will have been 
developed regardless of highway construction. The municipal op- 
erating costs attributable to this residential development will be 
partially offset by increased industrial and commercial expansion. 
Employment gains during this same period will add to the com- 
munity's revenues. It is expected that, because of expressway 
construction, employment will be increased by 1,000 jobs, the 
largest increase occurring in real estate, service-oriented activities 
and white-collar categories. 




IV-14 



INNER BELT AND EXPRESSWAY SYSTEM 



»J 



C 



LEXINGTON 




BELMONT 



SOMERVILLE 














r " ni i'"ni' 



LEGEND 
RESIDENTIAL LOW DENSITY 

RESIDENTIAL HIGH DENSITY 

COMMERCIAL 

INDUSTRIAL 

PUBLIC 8 SEMI PUBLIC 



CAMBRIDGE 



PUBLIC 8 SEMI PUBLIC 
£&k2 OPEN SPACE 



VACANT 

RECOMMENDED LOCATION 
ALTERNATE LOCATION 



1000 



1000 2000 3000 4000 

I H I I 



SCALE IN FEET 



The internal structure of Arlington will not be affected by 
the construction of either the Recommended or Alternate Location 
of Route 3. The Recommended Location generally parallels the 
Arlington-Belmont town line while the Alternate Location generally 
follows the Arlington-Winchester town line. The anticipated popu- 
lation of 55,800 by 1975, will constitute the major share of 
Arlington's potential growth. Adding to Arlington's future costs 
will be a possible new school, accelerated street and utility de- 
velopment, provision for off-street parking in Arlington Center, 
and perhaps some new recreation areas. The most important 
factors contributing to an increase in future revenue will be modest 
industrial and commercial growth. There will be no disruption 
of Arlington's industrial base, because no commerce or industry 
will be disturbed by either the Recommended or Alternate Loca- 
tions of the Route 3 Expressway. 

In summary, the net effect on Arlington of the construction 
of the Expressway System will be advantageous. The construc- 
tion of the Route 3 Expressway and its extension to the Inner 
Belt will reduce travel time to all areas, thereby creating sub- 
stantial transportation advantages for Arlington's manufacturers. 
Growth in population and employment will increase property 
values throughout the community, particularly in Arlington Center 
and along the Boston and Maine Railroad. Since both locations 
of the Expressway System border the Town, they minimize the 
initial dislocations and will permit continued and orderly develop- 
ment of Arlington. 



Exhibit S-9 
ARLINGTON LAND USE, 1959 



NNER BELT AND EXPRESSWAY SYSTEM 



IV-15 



EVERE 



NEEDHAM 



DEDHAM 




RESIDENTIAL LOW DENSITY 
RESIDENTIAL HIGH DENSITY 
COMMERCIAL 
INDUSTRIAL 

PUBLIC S SEMI PUBLIC 

!1 PUBLIC a SEMI PUBLIC 
OPEN SPACE 

VACANT 

RECOMMENDED LOCATION 

ALTERNATE LOCATION 



*^0^1Q^ 



OUINCY 



IV-16 



Exhibit S-10 
BOSTON LAND USE, 1959 



INNER BELT AND EXPRESSWAY SYSTEM 



i?R 



V 



BOSTON 

The present population and employment in Boston are ap- 
proximately 697,200 and 443,600, respectively. The rate of 
population growth has been declining. However, this trend is 
being arrested by the local planning activities and new express- 
ways. Without construction of the Expressway System, Boston's 
population will be approximately 709,000 and employment op- 
portunities 515,000 in 1975. With the construction of the Ex- 
pressway System the population will increase to 720,000 and 
employment opportunities to 529,000. These projections indicate 
that completion of the Expressway System will stimulate both 
population and employment growth. 

The expansion of non-profit facilities will probably be ac- 
celerated by the improvement in travel time between the city and 
the suburbs. An increase in economic activity will result in the 
need for additional off-street parking areas and local street im- 
provements. The population increase will require the increase of 
some municipal services. Costs of these services will be balanced, 
as the increases in community revenue are realized through new 
commercial and industrial development which will take place in 
response to an energetic and comprehensive renewal program. 

City officials, as well as many private citizens, are presently 
engaged in a comprehensive program of urban renewal, com- 
mercial expansion and industrial development, which will make 
a significant contribution toward the rebirth of Boston. This is 
evidenced by the development of the Prudential Center, the Gov- 
ernment Center, the West End Development and numerous other 
commercial, industrial and residential complexes. These develop- 
ments will in turn encourage voluntary rehabilitation of the sur- 
rounding areas. This program is already encouraging the modest 
return of families from suburban areas. 

Boston will be affected by the Recommended and Alternate 
Locations of the Inner Belt, the Southwest Expressway and, to a 
limited degree, by the Northern Expressway. The impacts attrib- 
utable to construction will be substantially eased by the oppor- 
tunities afforded by coordination of expressway construction with 
urban renewal projects. 



The Recommended Location of the Inner Belt generally follows 
the Ruggles Street corridor. This corridor presents complex prob- 
lems with respect to the many institutions which border it, notably 
Northeastern University, The Greek Orthodox Cathedral, Went- 
worth Institute, St. John of Damascus Church, the Boston Museum 
of Fine Arts, the Gardner Museum, Simmons College, Emmanuel 
College and Boston University. Through cooperation with officials 
of these institutions, their problems have been considered in the 
development of this Study. 

The Alternate Location of the Inner Belt generally follows 
the Tremont Street corridor, in general conformity with the 1948 
Master Plan. As with the Ruggles Street corridor, this location 
also presents complex problems with respect to the many institu- 
tions located along its path, including the Mission Church, Long- 
wood-Harvard Medical complex, and Boston University. The 
problems of these institutions were also considered in the develop- 
ment of the Alternate Location. The location of the expressway 
along the Tremont Street corridor bisects the area remaining for 
the expansion of the Longwood-Harvard Medical complex. 

The Recommended Location of the Southwest Expressway 



generally follows the mainline New York, New Haven and Hart- 
ford Railroad, without appreciably affecting the urban structure 
of the area. The Alternate Location essentially parallels Wash- 
ington Street and Hyde Park Avenue to Cummins Highway, thence 
parallels Huntington Avenue, Hyde Park and the Neponset River 
to Route 128. Among the facilities located in the Southwest Ex- 
pressway corridor are Arnold Arboretum, Forest Hills Cemetery, 
New England Hospital and Notre Dame Academy. 

In summary, the effects of the construction of the Express- 
way System on Boston will be highly advantageous. A vigorous 
program of industrial and commercial redevelopment, coordinated 
with this system, which will provide maximum access to transpor- 
tation arteries serving the metropolitan, New England, national 
and world markets, will enable Boston to compete favorably with 
the outlying communities. Real estate values will increase and 
the demand for office space will also increase. Along with ex- 
pressway construction, the present energetic and comprehensive 
programs of urban renewal and commercial and industrial de- 
velopment will provide the foundation for a better balance in 
the future economic structure of Boston. 




INNER BELT AND EXPRESSWAY SYSTEM 



IV-17 



BELMONT 

The present population and employment in Belmont are ap- 
proximately 28,700 and 4,000, respectively. The presently sta- 
bilized population of Belmont is not expected to continue, and a 
limited rate of growth is anticipated. Without construction of 
the Expressway System, the population of Belmont in 1975 will 
be 33,000, and the employment 4,600. With construction of 
the Expressway System the population growth will be limited to 
32,000; however, employment opportunities will increase to 5,400. 

The Belmont Hill area, the only sizeable tract available for 
residential development, offers the greatest potential for accom- 
modating the increase in population. The land in this area is 
subject to restrictions which require a substantial investment for 
home construction. Prospective purchasers of modestly priced 
homes will, therefore, seek locations in the outlying towns be- 
cause construction of the Expressway System will make these 
communities more attractive for residential development. More 
than 200 additional residential acres could be developed by 
1975, but construction of the Expressway System will limit this 
to approximately 160 acres. 

The major employment gains are expected in local govern- 
ment and in service-oriented industries. The increase in local 
employment will stimulate expansion of the retail facilities in Bel- 
mont Center and in Waverly and Cushing Squares, and of the 
establishments contiguous to Route 60 and the Concord Turnpike. 
The increased demand on these facilities will, in turn, create the 
need for additional off-street public parking areas. The addi- 
tional tax revenues realized from home construction in the Bel- 
mont Hill area are expected to balance the increased costs of 
the additional municipal services that will be required. 

In summary, the net effects of the construction of the Ex- 
pressway System are so modest that it is difficult to assign re- 
sponsibility for them specifically to the construction of the system. 
A reduced rate of population growth and increased employ- 
ment will enable Belmont to continue its sound financial position. 

Exhibits- 11 
BELMONT LAND USE, 1959 



LEXINGTON 




WALTHAM 




ECT5 



LEGEND 

RESIDENTIAL LOW DENSITY 

RESIDENTIAL HIGH DENSITY 

COMMERCIAL 

INDUSTRIAL 

PUBLIC ft SEMI PUBLIC 

PUBLIC a SEMI PUBLIC 
OPEN SPACE 

VACANT 

RECOMMENDED LOCATION 



WATERTOWN 



IOOO 



1000 



<-» I-* *-* 



2000 

— * 



3000 

I 



4000 



SCALE IN FEET 



IV- 18 



NNER BELT AND EXPRESSWAY SYSTEM 



Bo< 



§PST , 



BOSTON 



NEWTON 




LEGEND 
RESIDENTIAL LOW DENSITY 



^i RESIDENTIAL HIGH DENSITY 
COMMERCIAL 
INDUSTRIAL 



NEWTON 



PUBLIC a SEMI PUBLIC 

PUBLIC a SEMI PUBLIC 
OPEN SPACE 



VACANT 

RECOMMENDED LOCATION 

ALTERNATE LOCATION 



BOSTON 



4000 



SCALE IN FEET 



BROOKLINE 

The present population and employment in Brookline are 
approximately 54,000 and 12,000, respectively. The population 
has been declining over the past decade; however, that trend is 
not expected to continue. Without construction of the Expressway 
System, the 1975 population and employment will be approxi- 
mately 68,800 and 14,700, respectively. With construction of 
the Expressway System the population growth is expected to be 
limited to 65,000 but employment will be stimulated to 16,200. 
Of the expected increase of 1,500 workers, the majority will be 
employed in service-oriented industries. With few vacant land 
areas remaining, the population growth, when converted to hous- 
ing, will take the form of residential conversion and apartment 
construction, thus increasing residential densities. It is expected 
that this growth will be comprised of small families which will 
require minimum municipal services. 

The Recommended Location of the Inner Belt Expressway 
will have little effect on the physical structure of Brookline. The 
Alternate Location, however, will seriously alter the structure of 
Brookline by isolating the eastern portion of the town, including 
the Cottage Farm area. 

In summary, the net effects on Brookline of the construction 
of the Recommended Location of the Inner Belt will be advanta- 
geous. Although the rate of community growth will be reduced 
by expressway construction, Brookline will maintain its solid com- 
petitive economic position in the Boston Metropolitan Area. Local 
retail and service outlets will expand by more than 30 acres to 
serve the surrounding communities. A reduced rate of population 
growth and increased employment will provide a better future 
balance of municipal service costs and revenues. Construction 
of the Inner Belt in the Recommended Location will prevent further 
commercial encroachments on the Cottage Farm Area, remove 
a large portion of the through traffic from local streets in Brook- 
line, and permit the Town to plan effectively for its future ex- 
pansion. 

Exhibit S-l 2 
BROOKLINE LAND USE, 1959 



INNER BELT AND EXPRESSWAY SYSTEM 



IV-19 



BURLINGTON 

The present population and employment in Burlington are 
approximately 13,000 and 3,300, respectively. Construction of 
the Expressway System will result in a reduction of the present 
rate of residential development in Burlington. However, the ex- 
tension of Route 3 will assure that Burlington will still realize a 
substantial future growth. Without construction of the Express- 
way System, the 1975 population and employment will be 15,900 
and 4,400, respectively. With construction of the Expressway 
System the future population will be limited to 14,500 but em- 
ployment will expand to 4,800. 

A reduced population growth rate through 1975 will lower 
future operating costs, thereby permitting Burlington to stabilize 
its economy and facilitate orderly completion of its capital im- 
provement program. For example, the reduced rate of popula- 
tion growth will eliminate the necessity for having to provide 
municipal services for at least 200 residential acres. Employment 
gains during the same period will add to the community's revenues. 
While the largest increase in employment will occur in the elec- 
trical machinery industry, increases can also be expected in retail 
employment, research and development industries, and in service- 
oriented activities. A better economic balance will result from 
a reduced rate of population growth and its resulting economies, 
coupled with a rise in property values in the area contiguous to 
Routes 3 and 128, resulting from new plant and shopping center 
construction. 

In summary, the net effect on Burlington of the construction 
of the Expressway System will be highly advantageous. The lessen- 
ing of its growth rate through 1975 will enable Burlington to 
develop an integrated community that can be adequately served 
by public and private facilities without major increases in local 
property taxes. 



Exhibit S-13 
BURLINGTON LAND USE, 1959 




BEDFORD 

/ 


r \£ 
\ 


1 

1 
1 


\* ) 



WOBURN 



4000 



LEGEND 

RESIDENTIAL LOW DENSITY 

RESIDENTIAL HIGH DENSITY 

COMMERCIAL 

INDUSTRIAL 

PUBLIC S SEMI PUBLIC 

PUBLIC a SEMI PUBLIC 
OPEN SPACE 

VACANT 

RECOMMENDED LOCATION 

ALTERNATE LOCATION 



SCALE IN FEET 



IV-20 



INNER BELT AND EXPRESSWAY SYSTEM 



XBOSTO'N 

v 



if 
OEDHAM I /^ ^y \ 



I 



■ 



WESTWOOD 



LEGEND 
RESIDENTIAL LOW DENSITY 

RESIDENTIAL HIGH DENSITY 

COMMERCIAL 

INDUSTRIAL 

PUBLIC a SEMI PUBLIC 

PUBLIC a SEMI PUBLIC 
OPEN SPACE 

VACANT 

RECOMMENDED AND 

ALTERNATE LOCATION 




NORWOOD Sj>/ 



RANDOLPH 



*/ CANTON 

The present population and employment in Canton are ap- 
proximately 12,800 and 3,500, respectively. Without the Ex- 
pressway System, Canton's 1975 population and employment 
will be 16,400 and 3,900, respectively. Construction of the Ex- 
pressway System will stimulate both population and employment 
growth so as to increase the population to 18,000 and the em- 
ployment to 5,700 in 1975. By that time approximately 1,000 
additional residential acres will be developed, 200 acres of which 
are attributed to highway construction. Tax revenues from in- 
creased industrial and commercial development are expected 
to balance the increase in the cost of municipal services caused 
by this residential expansion. Growth is anticipated in local con- 
struction and retail activities. Local real estate interests will gain 
from increased land values, the largest increases occurring in 
the vicinity of the Route 128 interchange with the Southwest Ex- 
pressway. 

The Recommended and the Alternate Locations cross the 
Neponset River Reservation in Canton. The only notable physical 
effect will be a very slight decrease in available open space. 
In summary, the net effect on Canton of the construction of the 
Expressway System will be advantageous. The population growth 
will result in higher residential densities, which in turn may require 
improved and expanded town services. Without the Expressway 
System, the balance between net revenues derived from com- 
mercial and industrial activities and the net costs of servicing the 
residential areas would be less favorable for Canton. 



Exhibit S-l 4 
CANTON LAND USE, 1959 



INNER BELT AND EXPRESSWAY SYSTEM 



IV-21 




IV-22 



Exhibits- 15 
CAMBRIDGE LAND USE, 1959 



INNER BELT AND EXPRESSWAY SYSTEM 



<c.°&' 



^Rr 



CAMBRIDGE 

The present population and employment in Cambridge are 
approximately 107 ; 700 and 64,000, respectively. The population 
growth rate has been decreasing in recent years; however, this 
trend is not expected to continue. Without construction of the 
Expressway System the 1975 population and employment will 
be 114,000 and 87,600, respectively. With construction of the 
System, the 1975 population and employment will be 116,000 
and 115,000, respectively. The net effect of the Inner Belt and 
Expressway System will be to stimulate the employment growth 
of Cambridge. The potential increase in population is limited be- 
cause there are relatively few acres presently available for resi- 
dential development. The future population densities in the re- 
newal areas are estimated, in this Study, to be the same as at 
present. Thus the small increase in population growth will take 
place in the relatively few vacant residential areas, and through 
the construction of modern apartment buildings throughout the 
city. The projected large increase in economic activity and em- 
ployment will result from increased accessibility to the Boston 
Metropolitan Area via the Inner Belt and Expressway System. The 
projected increase in population and economic activity will pro- 
vide Cambridge with a broader tax base. While it is anticipated 
that the major share of this economic activity will be accommodated 
in existing and presently planned facilities, it is inevitable that 
most of the remaining vacant industrial acreage will be utilized. 
While major employment increases will occur in the research and 
development industries, increased employment will also occur in 
service-oriented activities. 

Cambridge is affected by the Recommended and Alternate 
Locations of the Inner Belt, Northwest and Route 3 Expressways. 
The effects of the Recommended and Alternate Locations of Route 
3 will be limited, due to the sparse development along Alewife 
Brook Parkway and in the vicinity of the interchange between 
Alewife Brook Parkway and Route 2. The alignment of the Alter- 
nate Location follows Alewife Brook; thus it will not disrupt exist- 
ing neighborhood boundaries or school, fire or police service 



districts. Both Locations will avoid the majority of the develop- 
ments along Alewife Brook Parkway. However, remaining vacant 
land is scarce and the proposed construction may affect the po- 
tential expansion of some firms located in the areas involved. 
The Recommended and Alternate Locations of the Northwest Ex- 
pressway basically parallel the Boston & Maine Railroad and 
will have little effect on the urban structure of the community. 
A number of commercial and industrial establishments, however, 
will be affected by each alignment. Relocation of these busi- 
nesses will depend on their current financial stability and the sta- 
bility of their particular market or field. 

The Recommended Location of the Inner Belt generally paral- 
lels the Brookline-Elm Street corridor passing through the Cam- 
bridgeport and Donnelly Field Renewal Areas. Much of the impact 
noted in these areas would have occurred under the normal sched- 
ule for renewal. Also, a number of commercial and industrial 
establishments contiguous to Brookline Street would have been 
affected by urban renewal. The Recommended Location will serve 
as a physical divider between industrial areas and will also pro- 
vide access to the industrial area, reducing truck traffic movements 
through the Cambridgeport area. Increased accessibility to re- 
gional highway networks, and active industrial planning by local 
officials, will probably induce the affected establishments to re- 
main within Cambridge. 

The most important effect of the Recommended Location of 
the Inner Belt to local business is the potential redevelopment of 
Central Square. An expressway with access to the Square will 
stimulate a comprehensive commercial development along Mas- 
sachusetts Avenue. Locally available labor, current renewal activi- 
ties and accessibility to other sections of the Study Area will 
provide the necessary attractions to sustain such a development. 
Improved economic conditions in Central Square will increase the 
value of commercial and industrial real estate and provide a 
stimulus for the construction of additional office space. Residen- 
tial properties in the vicinity of Central Square will be in high 
demand, and voluntary private rehabilitation will inevitably pro- 



ceed at a high level. 

Further development will result from increased activity in 
research and development industries. Transportation costs for 
manufacturing industries in Cambridge will decrease. An increase 
in manufacturing will result in concurrent favorable development 
in warehousing and trucking facilities. Cambridge is actively en- 
gaged in a program of commercial and industrial development, 
and the transportation advantages created by the Expressway 
System are necessary for the successful completion of this pro- 
gram. In this connection, the local government is actively inter- 
ested in an urban renewal program and has recently filed for 
approval to expand the Combridgeport Renewal Area. Realiza- 
tion of these plans will expand the potential economic base of 
the community. 

The Alternate Location of the Inner Belt in Cambridge is a 
two-level viaduct constructed over the Grand Junction Branch 
Railroad. Residents displaced in the lower Donnelly Field Area, 
for the most part, are located within the Donnelly Field Renewal 
Area and, under the urban renewal program, these families are 
eligible for relocation assistance. This location disrupts a number 
of commercial and manufacturing activities located adjacent to 
the railroad. Although this location cannot provide traffic service 
comparable to the Recommended Location because it causes traffic 
to travel longer distances on local streets, it does reduce resi- 
dential displacements. 

In summary, the net effects on Cambridge of the construc- 
tion of the Expressway System will be advantageous. The short- 
term physical effects can be lessened through proper use of avail- 
able means of public and private financing for replacement 
housing. Cambridge has actively coordinated its renewal plans 
with the Recommended Location to obtain the best practicable 
benefit from the expressway construction. Comprehensive local 
planning, increased commercial and industrial activities, and in- 
creased employment will enable Cambridge to expand its eco- 
nomic base and thus provide for a better balance between future 
revenues and costs. 



NNER BELT AND EXPRESSWAY SYSTEM 



IV-23 






of 



)—- — ._ BURU "GTON 



W'OBURN 



ESSWAY 






ARLINGTON 








\ 



IOOO 



v\M* 



IOOO 2000 3000 4000 



SCALE IN FEET 



IV-24 



Exhibit S-16 
LEXINGTON LAND USE, 1959 



LEGEND 

RESIDENTIAL LOW DENSITY 

RESIDENTIAL HIGH DENSITY 

COMMERCIAL 

INDUSTRIAL 

PUBLIC a SEMI PUBLIC 



PUBLIC 6 SEMI PUBLIC 







OPEN SPACE 

VACANT 

RECOMMENDED LOCATION 
ALTERNATE LOCATION 



INNER BELT AND EXPRESSWAY SYSTEM 



LEXINGTON 

The present population and employment in Lexington are 
approximately 27,700 and 3,200, respectively. The population 
growth has increased rapidly over the past decade, but con- 
struction of the Expressway System is expected to decelerate the 
present rate of population growth. Without construction of the 
Expressway System, the 1975 population and employment will 
be 37,700 and 4,300, respectively. With construction of the 
Expressway System the population will be reduced to approxi- 
mately 34,000, while employment opportunities will increase to 
9,700. Therefore, construction of the Expressway System will re- 
duce Lexington's 1975 population by 3,700, but will increase 
employment by 5,400 over what might otherwise be anticipated. 
The Recommended and Alternate Locations for the Route 3 
Expressway will result in substantially different distributions of 
population and employment. The Recommended Location, which 
passes northeast of Lexington Center, will result in residential as 
well as commercial development around the Center and along 
the areas adjacent to Route 2. The Alternate Location, which 
passes through the northern section of Lexington, will sustain and 
perhaps stimulate the present development trends in that section 
of the town. The location of the Route 3 Expressway will also 
determine the area of greatest increase in property value. Con- 
struction of the Recommended Location is expected to concentrate 
the greatest commercial development in and around Lexington 
Center while affecting only one industrial establishment. The 
Alternate Location, along the northern border of Lexington, will 
create opportunities for convenience-shopping centers, particularly 
in the northeast corner of the town. Since a substantial portion 
of the anticipated increases in employment are expected in white- 
collar categories, construction of either the Recommended or 
Alternate Location will create a desire for office space in and 
around Lexington Center. Property values in the vicinity of Route 
128 at the intersection of Route 3 will further increase when the 
extension of the Route 3 Expressway is completed. 

The Recommended Location has the greatest potential for 
reducing traffic congestion in Lexington Center. Furthermore, 
since it passes through a relatively undeveloped corridor, there 



will be no appreciable effect on existing police, fire and school 
service districts. Lexington has plans to develop a major street, 
Emerson Road, in approximately the same location as recom- 
mended for Route 3. Integration of these plans with the plans 
for the Recommended Location of Route 3 will provide substantial 
savings to the Town, both in direct construction and future street 
maintenance costs. These savings can be realized without sacri- 
ficing traffic service or creating a physical barrier between sec- 
tions of the Town. Bridges on the Recommended Location at 
Adams Street, East Street, Woburn Street, Maple Street and at 
Massachusetts Avenue will maintain present local traffic circula- 



tion patterns. Interchanges at Woburn Street and Massachusetts 
Avenue will provide the center of Lexington and the residential 
areas with convenient and desirable access to the Expressway 
System. 

In summary, the net effect on Lexington of the construction 
of the Expressway System is advantageous. The reduction in 
population growth rate will correspondingly reduce future require- 
ments for municipal services and projected employment will 
increase. The benefits of the expansion of commercial and manu- 
facturing activities by more than 150 additional acres will result 
in an improved future financial status for the town. 




INNER BELT AND EXPRESSWAY SYSTEM 



IV-25 



MEDFORD 

The present population and employment in Medford are 
approximately 65,000 and 10,000 7 respectively. The popula- 
tion has declined over the past decade, but it is anticipated that 
benefits resulting from the construction of the Expressway Sys- 
tem, together with active local planning, will arrest the present 
trend. Without construction of the Expressway System, Medford 
could anticipate a 1975 population approximately the same as 
at present, but an increase in employment opportunities to 13,600. 
With construction of the Expressway System the population will in- 
crease slightly to about 68,500; however, it will appreciably in- 
crease employment by providing opportunities for 1,600 addi- 
tional, or a total of 15,200. The expressway construction will 
increase the amount of land utilized for industrial and commercial 
activities, thus resulting in the above-mentioned increased em- 
ployment. These increases are expected to provide a favorable 
balance between revenue from industrial expansion and added 
costs due to residential development. 

The Recommended Location for the Route 3 Expressway will 
not enter Medford. The Alternate Locations for the Route 3 Ex- 
pressway along the Mystic River Valley will not affect the physical 
structure of Medford, except that substitute recreational facilities 
will have to be provided for its southern residential section. This 
problem requires consideration because Medford was previously 
deprived of other recreational facilities in the construction of the 
Northern Expressway. The Metropolitan District Commission pres- 
ently has under study plans to develop a fresh-water basin in the 
Mystic River estuary for flood control and recreational purposes, 
similar to that on the Charles River. The successful completion 
of this project will eliminate the present tidal fluctuations in the 
estuary, thereby enhancing the value of the surrounding residen- 
tial and commercial properties. The increased attractiveness of the 
area will provide the stimulus for residential, commercial and rec- 
reational developments in the area surrounding this basin. 



Exhibit S-17 
MEDFORD LAND USE, 1959 




i 






LEGEND 

RESIDENTIAL LOW DENSITY 
RESIDENTIAL HIGH DENSITY 



COMMERCIAL 
INDUSTRIAL 



EVERETT 



I PUBLIC a SEMI PUBLIC 



PUBLIC a SEMI PUBLIC 
OPEN SPACE 



VACANT 

RECOMMENDED LOCATION 

ALTERNATE LOCATION 



1000 



1000 2000 3000 4000 



SCALE IN FEET 



IV-26 



NNER BELT AND EXPRESSWAY SYSTEM 




Sfe 




LEGEND 

RESIDENTIAL LOW DENSITY 
RESIDENTIAL HIGH DENSITY 
COMMERCIAL 
INDUSTRIAL 

PUBLIC & SEMI PUBLIC 

PUBLIC 8 SEMI PUBLIC 
OPEN SPACE 

VACANT 



RECOMMENDED AND 
ALTERNATE LOCATION 



RANDOLPH 






In summary, the net effect on Medford of the construction 
of the Expressway System will be advantageous. Channeling of 
through-traffic onto the Expressway System will keep local traffic 
congestion manageable within the forecast period. Increased 
employment opportunities and limited population increases will 
assure a continued favorable financial balance. 

MILTON 

The present population and employment in Milton are ap- 
proximately 26,400 and 2,000, respectively. The population has 
increased within the past decade; however, construction of the 
Expressway System will reduce the rate of population growth, 
since other communities will gain greater relative advantages 
from construction of the System. Without construction of the 
Expressway System, the population and employment in 1975 are 
estimated to be 36,500 and 2,200, respectively. With construc- 
tion of the Expressway System, Milton's 1975 population and 
employment will be 33,000 and 2,900, respectively. While con- 
struction of the System will reduce the rate of population growth, 
employment during the same period will be stimulated. 

More than 1,000 additional residential acres could be de- 
veloped in Milton by 1975; however, construction of the Express- 
way System is expected to limit this to approximately 650 acres, 
as a result of the relative attractiveness of other communities. 
This lessened rate of population growth will result in at least 350 
residential acres, with a potential for housing more than 1,000 
families, remaining undeveloped with commensurate reduction in 
future needs for municipal services. Employment gains during 
the same period will add to the community's revenues. It is ex- 
pected that expressway construction will increase employment by 
700, the largest increases occurring in service-oriented industries 
and real estate. The Recommended and Alternate Locations of 
the Southwest Expressway are in the Neponset River Reserva- 
tion in the extreme western corner of Milton, and will not result 
in any measurable physical effect upon the town. 

Exhibit S- 18 
MILTON LAND USE, 1959 



INNER BELT AND EXPRESSWAY SYSTEM 



IV-27 



ARLINGTON ' 



UR BAN RENEWAL AREAS 

RENEWAL 

B) renewal, industrial a 

COMMERCIAL DEVELOPMENT 
INDUSTRIAL DEVELOPMENT 




EVERETT 






^____ 



.•h< 



, — 



CAMBRIDGE 



IOOO o 



1000 2000 



3000 4000 
i- 1 



SCALE IN FEET 



LEGEND 

RESIDENTIAL LOW DENSITY 

RESIDENTIAL HIGH DENSITY 

COMMERCIAL 

INDUSTRIAL 



PUBLIC 8 SEMI PUBLIC 

PUBLIC a SEMI PUBLIC 
OPEN SPACE 



VACANT 

RECOMMENDED LOCATION 

ALTERNATE LOCATION 



IV-28 



Exhibits- 19 
SOMERVILLE LAND USE, 1959 



INNER BELT AND EXPRESSWAY SYSTEM 



In summary, the net effect on Milton of the construction of 
the Expressway System will be advantageous. Milton will benefit 
from a reduced rate of population growth and increased em- 
ployment opportunities created by construction of the expressways. 
The Town is a well-planned community in sound financial condi- 
tion. Controlled growth and coordinated planning, coupled with a 
reduced requirement for future municipal services, together with 
added employment opportunities will readily permit Milton to 
balance future community revenues and costs. 

SOMERVILLE 

The present population and employment in Somerville are 
approximately 94,700 and 20,500, respectively. The rate of pop- 
ulation growth has been declining in recent years. However, 
transportation advantages created by the Expressway System, 
together with active local planning, will cause this downward 
trend to level off. Without construction of the Expressway System, 
the 1975 population and employment will be 99,500 and 24,500, 
respectively. With construction of the System the 1975 population 
and employment will be 98,500 and 26,000, respectively. 

There are few vacant, buildable areas remaining in Somer- 
ville, and the future population, when converted into housing, will 
take the form of apartment construction and residential conversion. 
The smaller population growth resulting from expressway con- 
struction will mean that the future requirements for municipal 
services will be correspondingly less. Employment gains during 
the same period, together with industrial and commercial expan- 
sion, will add to the community's revenues. The major employment 
increases are anticipated in transportation, service-oriented, whole- 
sale-trade and machinery activities. 

Somerville is affected by the Recommended and Alternate 
Locations of the Inner Belt, Northwest and Northern Expressways. 
The Recommended and Alternate locations of the Northwest Ex- 
pressway basically parallel the Fitchburg Division of the Boston 
& Maine Railroad. Either location will leave a small section in the 
Lincoln Park Area located between the Northwest Expressway 
and the railroad. The Recommended Location of the Northern 
Expressway generally parallels Mystic Avenue, running along the 



edge of the Ten Hills area. The Alternate Location skirts the Ten 
Hills area and generally parallels Middlesex Avenue. This 
location bisects the Mystic River Basin and may have a serious 
effect on the development of this basin as a scenic and recreational 
area. Plans for a flood-control project for this basin have already 
been authorized by the Legislature. The Recommended Location 
of the Inner Belt is basically within the Boston & Maine Railroad 
yards, and will have little effect upon the existing industrial and 
residential development of the community. The Alternate Location 
is basically north of the Boston & Maine Railroad yards, and will 
have a greater effect on the residential area than will the Recom- 
mended Location. 

One of the objectives of Somerville, in recent years, has been 
to attract more industry to the City. Some of the manufacturing 
activities affected by expressway construction occupy outmoded 
plants, and may desire to modernize their operations in new plants 
in other locations. An active program of local commercial and 
industrial redevelopment planning, and the transportation advan- 
tages resulting from the expressway construction, will make it at- 
tractive for these and other industries to locate in Somerville. 
Construction of the Expressway System is not expected to affect 
appreciably the total retail commerce in Somerville, although some 



shops and a small shopping center along Mystic Avenue will be 
affected. 

In summary, the net effect on Somerville of the construction 
of the Expressway System will be advantageous. In order for the 
City to arrest its decline, an active program in urban redevelop- 
ment and renewal must be pursued. The construction of the 
Expressway System presents an opportunity for the City to under- 
take such a program effectively and to realize over-all community 
objectives. 

The Expressway System will tend to remove through-traffic 
movements, particularly trucking, from local streets. This will im- 
prove the opportunity for the success of local business and urban 
renewal programs. The present balance between local govern- 
ment revenues and costs should be substantially the same in 1975, 
provided revenues added by industrial expansion are utilized for 
urban renewal. When urban renewal has been effected, local 
buying power will be considerably increased, thus yielding added 
revenues to local merchants. Land values will increase in and near 
the Boston & Maine Railroad yards and in the areas contiguous to 
the Expressway System. Increased access to a national transporta- 
tion network will enable Somerville's industries to consolidate their 
competitive positions. 






w* 









* 




Trance 



NNER BELT AND EXPRESSWAY SYSTEM 




IV-29 



WINCHESTER 

The present population and employment in Winchester are 
approximately 19,400 and 2,700, respectively. It is anticipated 
that the present rate of growth will continue. The construction 
of Routes 128 and 3 in past years stimulated the rapid growth of 
Burlington and Woburn but did not appreciably affect Winchester. 
The completion of the Route 3 Expressway will also have little in- 
fluence on the population growth of Winchester but could produce 
a measurable increase in employment growth. Without construc- 
tion of the Expressway System, the 1975 population and employ- 
ment will be 25,000 and 4,000, respectively. With construction of 
the expressways the 1975 population will also be 25,000 but 
employment will increase to 5,400. The employment increase is 
dependent upon the town taking specific action to attract additional 
commercial and industrial development by increasing the amount 
of land zoned to permit these activities. Without this change 
in zoning, the employment increases may be limited to only 500. 

The Recommended Location for Route 3 will not pass through 
Winchester, and therefore no physical effects will result. The 
Alternate Location will reduce available recreation areas, since 
it will pass through the Winchester Country Club and the Mystic 
Lakes. If the expressway is so located, the town may be able to 
purchase the remaining holdings of the country club, or other 
areas may be obtained, to provide facilities for the southwest 
section of town. Under either arrangement additional capital ex- 
penditures will be involved. 

In summary, the net effect of the construction of the Express- 
way System on Winchester will be advantageous. Construction 
of the Expressway System will reduce the through traffic on Win- 
chester's local street system and increase the employment potential 
in Winchester, which will enable it to continue its present sound 
financial position. 



Exhibit S-20 
WINCHESTER LAND USE, 1959 




: _ 



F^^ 

&&L3& 



LEGEND 

RESIDENTIAL LOW DENSITY 

RESIDENTIAL HIGH DENSITY 

COMMERCIAL 

INDUSTRIAL 

PUBLIC 8 SEMI PUBLIC 

PUBLIC a SEMI PUBLIC 
OPEN SPACE 

VACANT 
ALTERNATE LOCATION 






WOBURN 




IV-30 



INNER BELT AND EXPRESSWAY SYSTEM 



*<* *t 



WILMINGTON 




STONEHAM 



LEGEND 

:Z4 RESIDENTIAL LOW DENSITY 



■ ' ■ 
- 




Km 


."■ 




hm 



loqo o 

m « 1-1 



2000 



4000 



RESIDENTIAL HIGH DENSITY 

COMMERCIAL 

INDUSTRIAL 

PUBLIC 8 SEMI PUBLIC 

PUBLIC a SEMI PUBLIC 
OPEN SPACE 

VACANT 

ALTERNATE LOCATION 



SCALE IN FEET 



WOBURN 

The present population and employment in Woburn are ap- 
proximately 31,200 and 6,700, respectively. Residential growth 
has increased rapidly in the past decade and this high growth 
rate is expected to continue. Without construction of the Express- 
way System the 1975 population and employment of Woburn will 
be 33,600 and 7,800, respectively. With construction of the 
expressways the 1975 population and employment will be 34,500 
and 10,600, respectively. 

Approximately 300 additional residential acres can be de- 
veloped by 1975, of which 75 acres are considered attributable to 
highway construction. While construction of the Expressway Sys- 
tem will stimulate population growth only nominally, it is anticipated 
that future employment in Woburn will be greatly stimulated. The 
major employment increases are expected in the electrical ma- 
chinery and chemical industries and in service-oriented activities, 
an expansion amounting to more than 360 acres of new develop- 
ment. The construction of the Route 3 Expressway will have little 
effect on the existing structure of Woburn. The Recommended 
Location will not pass through Woburn, and the Alternate Location 
passes through the western corner of the town. No commercial 
or manufacturing activities will be affected by either location. 

In summary, the net effects on Woburn of the construction of 
the Expressway System will be advantageous. Increased tax 
revenues from commercial and industrial development will offset 
the increase in operating cost for added municipal services resulting 
from the increased population growth. Without construction of the 
Expressway System, the balance between future community rev- 
enues and costs would be less favorable. 



Exhibit S-21 
WOBURN LAND USE, 1959 



INNER BELT AND EXPRESSWAY SYSTEM 



IV-3 I 



SECTION 6 - SUMMARY AND CONCLUSIONS 



Continuous and accelerated urban and suburban growth have 
greatly aggravated existing problems of urban traffic congestion. 
Recognition of these problems has resulted in a necessary shift in 
federal and state emphasis from the construction of rural highways 
to the construction of urban expressways. The Federal Aid High- 
way Act of 1944, which provides federal assistance to states for 
the construction of urban highways, is the prime example of 
such recognition. The consideration of the social and economic 
effects of expressways upon a community, as a factor in the selec- 
tion of a specific location, is recognized by both Federal and 
State Governments. 

The purpose of the Socio-Economic Analysis in this Study was 
to determine the effects which alternative locations of the Inner 
Belt and Expressway System would have on the various communi- 
ties in the Economic Study Area. The first step of this analysis 
was the review of past studies that dealt with the evaluation of 
socio-economic effects of previous expressway construction. Most 
of these past studies were analyses of effects after completion of 
highway construction, and therefore provided guidance for the 
projection of future highway benefits, and focused attention on the 
effects and attendant problems that could be anticipated as a 
result of expressway construction in urban areas. 

The Socio-Economic Study Area is comprised of 121 cities 
and towns which will be serviced by several radial and three 
circumferential expressways. The analysis of this area includes 
the concurrent effect of many factors such as: 

a) The overall economic base, 

b) The shifting of population, 

c) Social characteristics, 

d) Political boundaries, 

e) Family income factors, 

f) The ability of the individual municipalities to control land 

use. 

To accomplish this analysis, a gravity model technique was de- 
veloped that encompassed the specific prevailing conditions. The 
analysis, though broad and complex, was unified by means of 
social science theories. The procedures and objectives involved 
consideration of alternative locations of the Inner Belt and Ex- 



pressway System which would maximize the system's contribution 
to the long-range growth and development of the cities and towns 
within its influence. The study furthermore involved a determination 
of benefits that would accrue to the individual communities fol- 
lowing the construction of the Expressway System. 

The results of the Socio-Economic Analysis showed that, in 
most cases, the functional effects were of minimal influence in the 
selection of the Recommended Location, because of the proximity 
of alternative locations within a corridor. However, the results 
of the analysis of the functional effects indicate that all communi- 
ties involved will benefit from the expressway system construction. 
The functional analysis provides understanding of the potential for 
development which the construction of the expressways can pro- 
vide for all communities within the Study Area. 

Population and employment projections and distributions for 
the year 1975 were made, both assuming construction of the 
Expressway System and assuming normal growth without construc- 
tion of the system. This procedure permitted the analysis of those 
effects which are directly attributable to construction of the ex- 
pressways. Only 13 communities will be physically affected by the 
location of the expressways within their boundaries. The effects 
on these communities were discussed in Section 5. Essentially con- 
current construction of the Expressway System will insure a small 
differential effect on the competitive positions of the individual 
cities and towns in the Study Area with relation to each other. 
Improved travel time between the Core Area and the suburbs will, 
in many instances, tend to cause residential development to pass 
over inlying communities having relatively high land costs, and con- 
centrate in the outlying cities and towns. Accordingly, the future 
distribution of population and employment will be more diffused. 

The Core Area will tend to attract, to an even greater degree, 
those industries dependent upon advantages of consolidation. Com- 
munication-oriented industries, and industries dependent upon a 
relatively unlimited labor pool, will inevitably find core sites more 
attractive. Transportation-oriented industries, presently located in 
and around the congested area, will greatly benefit from the im- 
proved transportation service provided by expressway construc- 
tion. It is considered that future suburban business growth will 



be comprised largely of convenience and standard retail outlets, 
consumer service facilities, highway transportation-oriented indus- 
tries which serve regional markets, and local government employ- 
ment. 

If the Expressway System is not constructed, and other trans- 
portation improvements are not made to the present network in 
the Boston Metropolitan Area, it is expected that population and 
economic activity will tend to concentrate generally in the areas 
in close proximity to the existing highways and other transporta- 
tion facilities. The Route 128 communities will, under this condition, 
continue their rapid growth, while outlying communities, not pres- 
ently being serviced by expressways, will offer less advantageous 
transportation facilities, and therefore will experience slower 
growth. Travel conditions throughout the area will deteriorate, 
contributing toward an accelerated decline of the Core Area and a 
retarded growth of the outlying suburban communities. Local de- 
velopment and redevelopment plans cannot, under these conditions, 
be brought to fruition, and the overall economy will be adversely 
affected. Increased transportation costs, due to traffic delays, 
will be reflected in the price of commodities, thus impairing the 
competitive position of the Boston Metropolitan Area with respect 
to New England and national markets. 

Expressways will be of maximum benefit to a particular 
community when the community effectively integrates its land-use 
plans with expressway locations. Therefore, realization of the 
full potential of the Expressway System is dependent upon the 
public and private agencies that are responsible for guiding the 
future development of each community. Expressways will make a 
significant contribution, but full development of potential resources 
can only be achieved if expressways are considered as a vital 
component of the overall transportation system that is required 
to serve the movement of people and goods. In order to achieve 
an integrated pattern of transportation services promoting eco- 
nomic growth, expressway construction must be coordinated with 
plans for port development, airport usage, and the future role of 
rapid transit and the railroads. In this connection, the movement 
of persons in dense urban areas must be served by both public 
and private modes of transportation. It is apparent that the 



IV-32 



NNER BELT AND EXPRESSWAY SYSTEM 



9. 



^RY 



Expressway System will not by itself solve the problems of trans- 
porting persons and goods within the Study Area. Construction 
of the system will result in a more even distribution of future 
population throughout the Study Area. It will become increasingly 
difficult to provide service for these new developments with ex- 
isting means and routes of transit service. It will be necessary to 
plan ahead continuously in recognition of future requirements, and 
to adopt the role and techniques of public transportation to the 
needs of the public. 

The Commonwealth of Massachusetts is currently undertaking 
a comprehensive program of expressway construction through 
densely populated urban areas. The successful completion of 
this program will give a new freedom of movement to the workers, 



shoppers, business men and residents, and promote the develop- 
ment of the economic potential of the entire Study Area. These 
benefits can be achieved with minimal difficulty for those who may 
be physically affected. Where household displacements are nec- 
essary, an urban renewal program can help to provide alternative 
accommodations. Through coordination of effort, the Common- 
wealth and the communities of the Boston Metropolitan Area can 
establish a program which, while achieving the long-term functional 
benefits, can also fully minimize the temporary physical effects, 
particularly those related to the necessary displacement of house- 
holders. This program will provide an opportunity to work to- 
gether in the construction of the vitally-needed Expressway System. 
It is important that a continuing record be kept of the actual 



economic advance of each community following the completion of 
the Inner Belt and Expressway System, by determining the extent 
of development in the several communities. This record would 
provide an empirical basis for continual refinement of the study 
methods employed in this analysis so they may be applied to 
similar socio-economic analyses in the future. 

The future form of the Study Area will be a series of resi- 
dential sectors radiating out from the Core Area, bordered by 
commercial activities which will develop along the Expressway 
System. The focal points of these developments will be the areas 
surrounding the interchanges between the radial and circumfer- 
ential expressways. Boston will remain the "hub" of the region, 
and, with the impact of current revitalization, will have a greater 
economic influence on the growing regional sub-centers. 







T.S.K 



NNER BELT AND EXPRESSWAY SYSTEM 



IV-33 





PART V 



EXPRESSWAY SYSTEM 



SECTION 1-THE INNER BELT EXPRESSWAY 



INTRODUCTION 



The basic functions of the Inner Belt Expressway are to serve 



as: 



a. A collector-distributor of vehicular traffic, to or from the 
various radial expressways, having origin or destination 
in the core area of Metropolitan Boston. 

b. An inter-connector for the transfer of vehicular traffic 
between the radial expressways for traffic with origin 
or destination either in Metropolitan Boston or on any 
part of the Interstate System. 

The diameter and corresponding length of the Inner Belt 
are predetermined by these basic functions. If the diameter were 
too large, the general location would be outside the core area of 
Metropolitan Boston, and hence would not effectively serve the 
major desire areas as a collector-distributor of traffic, and the bulk 
of this traffic would have to continue to use the existing street 
system for access to the core area. If the diameter were too 
small, it would not be possible to have all the radial express- 
ways connected directly to the Inner Belt and concurrently provide 
a sufficient number of local access ramps to distribute and collect 
traffic adequately. Ideally, the Inner Belt should be located as 
close as possible to the major traffic generators in the core area, 
and yet be of sufficient length to allow for connections with the 
radial expressways, as well as to provide for traffic service to and 
from the local streets. 

The location of the Inner Belt is governed by the highly im- 
portant physical location considerations in the heavily built-up, 
complex, urban area through which it must pass. The most im- 
portant physical controls are the two existing ends of the Central 
Artery and the location of the crossing of the Charles River. The 
general land-use controls existing along the Charles River, such 
as Boston University and other substantial real property on the 
south side, and Massachusetts Institute of Technology, Cambridge- 
port Urban Renewal Area, Harvard University, Morse School, Cam- 
bridge and Mount Auburn Cemeteries, and the United States 
Arsenal on the north side, limit the crossing of the Charles River 
to the area in the vicinity of the Boston University Bridge. This 
narrow range of possible crossings is compatible with a connection 




of the Inner Belt Expressway to the proposed extension of the 
Massachusetts Turnpike, and provides the required length of In- 
ner Belt to permit the connection of the several radial expressways 
and local ramps within the limits of the design criteria. 

With the general location of the control point of the Charles 
River crossing established, a review of previous reports and ex- 
tensive field reconnaissance were undertaken to determine feasible 
locations of the Inner Belt which would connect the following two 
terminal control points shown on Exhibit B-l: 

a. Southerly end of the Central Artery at Massachusetts 
Avenue in Roxbury, Terminal Control Point 1 . 

b. Northerly end of the Inner Belt extending from the Central 
Artery in Charlestown, Terminal Control Point 2. 

As a result of this review and reconnaissance, it was decided 
that a solution of the complex problem of determining feasible 
locations of the inner Belt could best be obtained by separating the 
locations studied into three geographical areas as follows: 

a. The Charles River crossing, including the interchange with 
the Massachusetts Turnpike. 

b. Boston and Brookline between the southerly Terminal Con- 
trol Point and the Charles River. 

c. Cambridge, Somerville, and Charlestown between the 
northerly Terminal Control Point and the Charles River. 

The three location controls, two of which fixed the end points 
and one which generally located the crossing of the Charles River, 
were strong motivation for separating the locations studied into 
three separate areas. Furthermore, the location of the Inner Belt 
in Boston and Brookline is independent of the location in Cam- 
bridge; however, the specific location of the Charles River crossing 
and the interchange with the Massachusetts Turnpike are de- 
pendent upon the location both in Boston and Cambridge. 

LOCATIONS OF THE CHARLES 
RIVER CROSSING 

GENERAL 

The Inner Belt crossing of the Charles River is confined to a 
limited area in the vicinity of the Boston University Bridge, because 
of the major land-use complexes on both sides of the river and the 



requirements for the optimum diameter as noted hereinbefore. 
Within this general area, there are several major considerations 
which vitally influence the specific location of the Charles River 
crossing. Major considerations on the south side of the river are: 

a. The extension of the Massachusetts Turnpike into Down- 
town Boston, its interchange in the Allston Yards of the 
New York Central Railroad, and the inter-connection of 
the Turnpike and the Inner Belt. 

b. Present and proposed buildings of Boston University and 
the preservation of its campus. 

c. The Commonwealth Armory, the Cadillac-Oldsmobile 
Building, the Boston University School of Fine and Applied 
Arts and the Cottage Farm section of Brookline. 

Major considerations on the north side of the river are: 

a. Present land uses along the river. 

b. The Urban Renewal Area between the Charles River and 
Massachusetts Avenue. 

Of various possibilities for entry into Cambridge, only two 
appeared feasible: at Brookline Street for those locations east of 
Central Square, and at River Street. Any other points of entry of 
the Inner Belt into Cambridge would seriously disrupt present and 
proposed development of the area between the Charles River and 
Massachusetts Avenue, and would require the acquisition of con- 
siderable high-value property by comparison. Further study re- 
vealed that the River Street location was not feasible, as described 
later. 

The Cadillac-Oldsmobile Building, the Commonwealth Armory, 
the Boston University School of Fine and Applied Arts and the 
commercial buildings along Commonwealth Avenue between Amory 
Street and Pleasant Street seriously restrict crossings of the river 
to the extent of channelizing the crossing to a few specific narrow 
corridors. Boston University's existing and proposed buildings pre- 
clude a bridge crossing of the Charles River downstream of the 
Boston University Bridge; however, a tunnel crossing would be 
possible in this location although it would pass beneath the pro- 
posed Boston University Library. The effect on the Cottage Farm 
area of Brookline would be minimized, provided the Expressway 
passed along the eastern and northern edge of this residential area. 



NNER BELT AND EXPRESSWAY SYSTEM 



V-l 



SUBSURFACE CONDITIONS 

All locations crossing the Charles River in the general vicinity 
of Boston University Bridge involve similar subsurface conditions. 
The subsoil in the immediate vicinity of the river is almost entirely 
dense and granular, with irregular and discontinuous strata of 
coarse sands and gravels interposed between deposits of fine sand. 
Within the limits of the river channel, the river bottom sediments 
consist of soft organic silts and sands upwards of 20 feet thick, 
underlain by the granular materials encountered along the banks. 
The depth to bedrock is more than 100 feet below channel bottom. 
Bridge foundations in such soils present no special problems other 
than requiring adequate precautions against scouring by the river. 
Excavation in the river for bridge foundations or for a cut-and- 
cover tunnel section, can best be effected by open excavation 
inside cofferdams, carried sufficiently deep into the dense granular 
materials, and sealed by tremie concrete. 

MASSACHUSETTS TURNPIKE CONNECTIONS 

Throughout this Study the uncertainty of the status of the 
extension of the Massachusetts Turnpike from Route 128 into the 
South Station area of Boston imposed the problem of determining 
an Inner Belt connection that would be compatible with either a 
toll facility or a free expressway to the west similar to the 1948 
Master Highway Plan recommendation. Many possible solutions 
of an Inner Belt connection to a free western expressway were 
considered in addition to connections to the Turnpike; these con- 
siderations increased the extent and complexity of the studies. 

Early in 1962, several conferences were held with repre- 
sentatives of the Massachusetts Turnpike Authority to review alter- 
native locations of an interchange of the Inner Belt and Turnpike. 
The arrangements between the Turnpike Authority and the New 
York Central Railroad concerning the joint use of the Allston Rail- 
road Yards precluded a bridge crossing of the Charles River 
entering Cambridge at River Street. Available space in the Allston 
Yards would be inadequate to accommodate the minimum railroad 
facilities, the Inner Belt, the Massachusetts Turnpike Extension and 
interchange connections to the Inner Belt, and the ramps for con- 
nection of the Massachusetts Turnpike to Cambridge Street in 



Allston. Since the Turnpike will be constructed before the Inner 
Belt, considerable additional construction costs will result from any 
alteration of the Turnpike. Possible river crossing locations were 
therefore restricted to the immediate vicinity of the Boston Univer- 
sity Bridge. 

DESCRIPTION OF RECOMMENDED 
AND ALTERNATE LOCATIONS 

Thirty alternative locations were developed in plan and 
profile, of which ten locations warranted further detailed study. 
This detailed study resulted in the selection of the Recommended 
Location, Alternate Designs I and II as practicable modifications of 
the Recommended Location, and an Alternate Location. 

The Recommended Location of the Charles River crossing be- 
gins on the south side of the River, at Beacon Street and Audubon 
Circle, as an elevated expressway in continuation of the Recom- 
mended Location of the Inner Belt in Boston. This location will 
curve to the west across a corner of Brookline, with the northbound 
roadway ascending to a position over the southbound roadway to 
cross the river upstream of the Boston University Bridge as a 
double-decked structure, and thence along Brookline Street in 
Cambridge. This location passes over the intersection of the Boston 
University Bridge and Commonwealth Avenue adjacent to the 
Cadillac-Oldsmobile Building. Connections west and south between 
the Turnpike and the Inner Belt are located over the New York 
Central Railroad on the Boston side of the river. Connections west 
and north are provided by a separate double-decked bridge up- 
stream of the Inner Belt crossing. 

Alternate Design I involves a tunnel crossing of the river. 
This location remains depressed after passing under Brookline Ave- 
nue in Boston, under the Highland Branch of the MTA, under Beacon 
Street and Mountfort Street and thence into a tunnel under the 
river, in a location which passes between the Boston University 
School of Theology and Student Union Building, now under con- 
struction, and beneath the proposed library. After crossing the 
river and entering Cambridge between 640 Memorial Drive and 
the Eastern Company building, the Expressway passes under 
Brookline Street and ascends to grade in a location parallel to 



Brookline Street. The connections to the Massachusetts Turnpike 
are depressed, and a considerable length of both the Turnpike 
and the railroad are also depressed a maximum of 19 feet so 
that the Inner Belt connections to the south can be located under 
Commonwealth Avenue. 

Alternate Design II is similar to the Recommended Location, 
except that the interchange is located on the south side of the 
river in Boston and Brookline instead of over the river. 

The Alternate Location of the Inner Belt crossing of the 
Charles River begins on the south side of the river, south of Com- 
monwealth Avenue, between Amory and Essex Streets, as an 
elevated expressway and as a continuation of the Alternate Loca- 
tion in Boston and Brookline. This location continues northward, 
crosses the Charles River as a two-level structure immediately up- 
stream of the Boston University Bridge, and enters Cambridge along 
the Grand Junction Branch of the New York Central Railroad. 
Connections west and south between the Turnpike and the Inner 
Belt cross Amory Street at Egmont Street, and pass between the 
Massachusetts National Guard maintenance sheds and the Com- 
monwealth Armory as a double-decked structure before entering 
the Allston Railroad Yards. Connections west and north cross Com- 
monwealth Avenue at Amory Street and again at St. Paul Street, 
thence joining with the Inner Belt-Turnpike connection to the south 
over the Armory Motor Pool as a double-decked structure. 

DESCRIPTION AND ANALYSIS 
OF OTHER LOCATIONS STUDIED 

ALTERNATIVE LOCATION A 

Alternative Location A represents a group of locations which 
connect a River Street location in Cambridge to either a Ruggles 
Street or Tremont Street location in Boston and Brookline. These 
alternatives were unacceptable due to the loss of commercial 
property in Brookline, the high cost of construction to cross the 
Turnpike facilities in the interchange area, and the severe impair- 
ment of the Allston Railroad Yards of the New York Central 
Railroad, as noted earlier in the discussions of the Massachusetts 
Turnpike Connections. 



V-2 



NNER BELT AND EXPRESSWAY SYSTEM 



INNER HARBOR 




INNER BELT AND EXPRESSWAY SYSTEM 




LEGEND 

IDENTIFICATION KEY 



4ry 



1— CITY HOSPITAL 

2 — GREEN SHOE MANUFACTURING COMPANY 

3 — ELIOT CEMETERY 

4— DUDLEY STATION (MTA) 

5 — MTA STORAGE AND MAINTENANCE 

FACILITIES 

6 — FIRST CHURCH IN ROXBURY 

7 — JAMES TIMILTY SCHOOL 
8 — MADISON PARK 

9— RUGGLES STREET BAPTIST CHURCH 
10— PUBLIC HOUSING 

11 —UNITED DRUG BUILDING (NORTHEASTERN 

UNIVERSITY) 

12 — PUBLIC HOUSING 
13_ WENTWORTH INSTITUTE 

14 — MUSEUM OF FINE ARTS 

15 — MUSEUM OF FINE ARTS SCHOOL 

AND ST. JOHN OF DAMASCUS CHURCH 

16 — GARDNER MUSEUM 

17 — BOSTON LATIN SCHOOL 

18 — SIMMONS COLLEGE 

19 — HARVARD MEDICAL SCHOOL 
20— PETER BENT BRIGHAM HOSPITAL 

21 _ EMMANUEL COLLEGE 

22 — BETH ISRAEL HOSPITAL 

23 — SEARS ROEBUCK & COMPANY 
24— LONGWOOD TOWERS 



25 — AMORY PLAYGROUND 

26— CADILLAC-OLDSMOBILE BUILDING 

27— COMMONWEALTH ARMORY 

28 — BOSTON UNIVERSITY 

SCHOOL OF FINE AND APPLIED ARTS 
29— PROPOSED LIBRARY, BOSTON UNIVERSITY 
30—640 MEMORIAL DRIVE 
31— JORDAN MARSH WAREHOUSE 

32 — MORSE SCHOOL 

33 — STOP & SHOP 

34 — B. B. CHEMICAL COMPANY 

35 — HOYT FIELD 

36 — CAMBRIDGE CENTRAL POST OFFICE 
37— CAMBRIDGE Y.M.C.A. 

38 — M.I.T. NUCLEAR REACTOR 

39 — M.I.T. MAGNET LABORATORY 

40 — METROPOLITAN STORAGE WAREHOUSE 

41 —CAMBRIDGE CITY HALL 

42 — CAMBRIDGE CITY HALL ANNEX 
43— PUBLIC HOUSING 

44 — M.I.T. TECHNOLOGY SQUARE 

45 — CAMBRIDGE CITY HOSPITAL 

46— DONNELLY FIELD & DONNELLY SCHOOL 
47_ PUBLIC HOUSING 

48 — COUNTY COURT BUILDINGS 

49 — SOMERVILLE INCINERATOR 

50 — GROISSER & SHLAGER IRON WORKS 



URBAN RENEWAL AREAS 



GENERAL NEIGHBORHOOD RENEWAL 
PLAN AREAS AND AREAS IN 
PRELIMINARY PLANNING. 

AREAS IN ADVANCE PLANNING. 

A — WASHINGTON PARK 

B — SOUTH END 

C — CHARLESTOWN 

D — DONNELLY FIELD 

E— HOUGHTON 

F — CAMBRIDGEPORT 



PROJECTS IN EXECUTION STAGE 

G — WHITNEY STREET 

H— PRUDENTIAL CENTER 

J _NEW YORK STREETS 

K — GOVERNMENT CENTER 

L — WEST END 

M— LINWOOD— JOY 

N— NORTH HARVARD 



- m 



MAJOR BUILDINGS & INSTITUTIONS 
SCHOOLS, CHURCHES 

PUBLIC RESERVATIONS, PARKS 
CEMETERIES, COUNTRY CLUBS 

RAILROADS & TRANSIT LINES 
CITY OR TOWN BOUNDARY LINES 

© CD & STATE - U S ' INTERSTATE ROUTES 

TERMINAL CONTROL POINTS 
EXISTING EXPRESSWAYS 
OTHER PROPOSED EXPRESSWAYS 
RECOMMENDED LOCATION 
ALTERNATE LOCATION 



ALTERNATIVE LOCATIONS STUDIED 



ft 



SCALE 

CONTOUR INTERVAL *0 FEET 
0ATUM IS ME*N SEA lEVEl 



Exhibit B-1 
INNER BELT STUDY LINES 



V-3 



ALTERNATIVE LOCATION B 

Alternative Location B represents a group of locations which 
connect a Ruggles Street location in Boston to a Brookline Street 
location in Cambridge by a tunnel located upstream of the Boston 
University Bridge. These alternatives were unacceptable as a re- 
sult of the greatly increased cost of construction, in excess of 
$55 million, necessary to provide: 

a. the additional length of tunnel and depressed roadway, 

b. extensive alterations required for the Turnpike interchange 
facilities, 

c. major revisions to the large existing and proposed sub- 
surface structures of the Metropolitan District Commis- 
sion's sewerage system in the area. 

ALTERNATIVE LOCATION C 

Alternative Location C represents a group of locations which 
involve a location of the interchange between the Turnpike and the 
Inner Belt on the north side of the river. These alternatives were 
unacceptable due to their severe effect on Cambridge and their 
inability to provide an adequate interchange for the Turnpike and 
Inner Belt. 

ALTERNATIVE LOCATION D 

Alternative Location D represents a group of locations which 
place the interchange of the Inner Belt and Turnpike within the 
Cottage Farm area of Brookline. These alternatives were unaccept- 
able due to the high cost of acquisition of right-of-way, and the 
impact on the Cottage Farm residential section and the commercial 
section along Commonwealth Avenue in Brookline. 

LOCATIONS IN 

BOSTON AND BROOKLINE 

GENERAL 

The area in Boston and Brookline between the terminus of the 
Central Artery at Massachusetts Avenue and the area available for 
the Charles River crossing has numerous general land-use and 
property-valuation controls. These controls include the Harvard 
Medical School complex, Boston Museum of Fine Arts, Northeastern 



University, Wentworth Institute, Emmanuel College, Simmons Col- 
lege, Gardner Museum, public housing projects, Kenmore Square 
business area, the business section around the Dudley MTA Station 
in Roxbury, Fenway Park, Sears, Roebuck and Company, the 
Ruggles Street Baptist Church, and the Green Shoe Manufacturing 
Company. Exhibit B-1 shows the various Inner Belt locations studied 
in this area and indicates that: 

a. A location close to downtown Boston and west of Massa- 
chusetts Avenue would pass through Northeastern Uni- 
versity's campus and either Kenmore Square or the hotel 
area east of Kenmore Square. The cost of right-of-way 
along such a location would be prohibitive. 

b. The Inner Belt could not be located between Ruggles 
Street and Tremont Street without destroying the integrity 
of the hospital and institutional complex around the 
Harvard Medical School. 

c. The Inner Belt could not be located west of Tremont 
Street, since Highland Park and Parker Hill create a topo- 
graphic barrier to such a location. A location west of 
Parker Hill would place the Inner Belt crossing of Beacon 
Street close to Coolidge Comer in Brookline, resulting in 
prohibitive right-of-way costs. In addition, extensive 
changes to Brookline's street pattern would be required 
to provide adequate local traffic service. 

Thus, it was obvious that only two locations warranted con- 
sideration. These are: 

a. Along Ruggles Street and The Fenway, 

b. Along Tremont Street and Francis Street. 

Another factor which greatly influences the location of the 
Inner Belt in Boston is the location of the interchange with the 
Southwest Expressway. All locations considered for the South- 
west Expressway enter the area of possible location of the Inner 
Belt either along Washington Street or along the New York, New 
Haven and Hartford Railroad. 

The Ruggles Street location of the Inner Belt passes through 
the lower Roxbury section of Boston, between Washington Street 
and Tremont Street at Madison Park. The area surrounding 
Madison Park contains many multi-family dwellings in very poor 



condition, and is programmed for urban renewal. Demolition is 
in progress within this area, since many of the buildings have 
become a menace to public safety and health due to lack of repair 
and maintenance. This area is therefore ideally suited for an inter- 
change between the two expressways. It is relatively flat; property 
values are extremely low; it is a sufficient distance from the South- 
east Expressway interchange to provide adequate spacing between 
major interchanges; and there are several major streets leading 
into downtown Boston to permit direct access to and from the 
Southwest Expressway, without requiring travel on the Inner Belt. 
The Tremont Street location has none of these advantages. 
The area available at the general location of the intersection of the 
two expressways contains a high hill and many important buildings 
and landmarks. However, while this location is unfavorable from 
the standpoint of the disruption of land-use patterns and physical 
impact on the area, it would result in a lower construction cost 
than that for the interchange in the Ruggles Street location, pri- 
marily because in this area the Ruggles Street location is depressed 
while the Tremont Street location is elevated. 

TOPOGRAPHY AND SUBSURFACE CONDITIONS 

The topography and geology existing along the locations in 
Boston and Brookline have important bearing on the comparative 
advantages of the locations studied. The only topographic fea- 
ture of serious consequence along the Ruggles Street location is 
Muddy River, which is relocated where it parallels the depressed 
expressway. The Tremont Street location is influenced primarily by 
Highland Park and by Parker Hill, which rises 175 feet above 
Tremont Street. This location also crosses Muddy River; however, 
the crossing is at right angles. Parts of both locations on the Bos- 
ton side of the Charles River generally parallel the rim of the Boston 
Basin. The Ruggles Street location is just within the Basin and the 
Tremont Street location passes along the shoulder of the rim. The 
subsurface profiles of each location are therefore markedly dif- 
ferent in character. 

Soil conditions for the Ruggles Street location are, in general, 
typical of the usual Boston Basin soils profile. Beneath a sur- 
face layer of shallow and random fill, peat of various depths 



V-4 



INNER BELT AND EXPRESSWAY SYSTEM 



generally overlies a deposit of Boston Blue Clay. The upper layer 
of the clay deposit consists of a crust of stiff desiccated clay, 
below which the consistency is soft. A layer of glacial till is gen- 
erally encountered below the clay deposit, and this layer of till 
overlies the bedrock. The depths to bedrock vary, and in some 
places are up to 250 feet below the surface. The Ruggles Street 
location traverses the peat-filled valley of the Muddy River in the 
vicinity of the Fenway. Much of the land along this location was 
created by the filling of marsh areas. Northerly of Beacon Street, 
the soil conditions are generally good, with a relatively thin layer 
of fill overlying granular materials ranging from fine sand to coarse 
gravel. These granular soils overlie the bedrock which rises sharply 
to within 40 feet of the surface under Commonwealth Avenue, 
thence falling precipitously away to the north. The water table 
is relatively high along the Ruggles Street location in the area from 
Columbus Avenue to Beacon Street. Appropriate design and adop- 
tion of suitable construction techniques, with particular emphasis 
on controlled dewatering, will permit use of a depressed roadway. 
The Tremont Street location involves frequent rock outcrop- 
pings from east of Columbus Avenue to Huntington Avenue and, at 
both ends of this line, there is a discontinuous sheet of till under 
a haphazard distribution of surface deposits ranging from peat 
to dense sand and gravel. Peat deposits are most prominent be- 
tween Massachusetts Avenue and Washington Street, and in the 
vicinity of the Muddy River. 

DESCRIPTION OF RECOMMENDED AND 
ALTERNATE LOCATIONS 

The Ruggles Street and the Tremont Street locations are de- 
scribed below as the Recommended Location and the Alternate 
Location, respectively. Numerous alternatives to the basic Ruggles 
Street location were studied in detail to ascertain the most advan- 
tageous design for the Ruggles Street location. The most advan- 
tageous alternative locations are presented as Alternate Designs 
I and II to provide comparisons with the applicable portions of 
the Recommended Location. 

The Recommended Location of the Inner Belt in Boston, re- 
ferred to as the Ruggles Street Location, is along the east side of 



Ruggles Street and The Fenway. This location begins at the south- 
erly end of the Central Artery, passes over Massachusetts Avenue, 
and turns westward to pass under Washington Street at Hunneman 
Street. The elevated Forest Hills-to-Everett MTA rapid transit line 
precludes a location of the Inner Belt over Washington Street. The 
Recommended Location interchanges with the Southwest Express- 
way at Madison Park and continues as a depressed expressway 
beneath Tremont Street, Columbus Avenue, and the New York, 
New Haven & Hartford Railroad, and thence parallel to and along 
the east side of Ruggles Street to Parker Street, where the two 
roadways diverge to pass on both sides of the block of buildings 
bounded by Huntington Avenue, Louis Prang Street, The Fenway 
and Museum Road, in order to preserve the Museum School, St. 
John of Damascus Church and Parish House, and a block of apart- 
ments. At Huntington Avenue where the two roadways diverge, 
two separate tunnels, one for each roadway, are provided so as 
to maintain over the expressway the collector-distributor road sys- 
tem which is continuous from Massachusetts Avenue to Common- 
wealth Avenue. Immediately after passing the Museum School, the 
separate roadways converge to pass under Park Drive and Brook- 
line Avenue. This location then ascends after passing Brookline 
Avenue, so as to pass over relocated Muddy River, the Highland 
Branch of the MTA, and Beacon Street just west of Park Drive. The 
Beacon Street subway portal is relocated approximately 500 feet 
westerly to eliminate a collector-distributor road and mass transit 
grade crossing. The Recommended Location from Beacon Street 
across Commonwealth Avenue to the Charles River was described 
earlier for the Charles River crossing. 

Alternate Design I involves a variation in the design of the 
interchange with the Southwest Expressway, and differs from the 
Recommended Location in this area in that it crosses over Columbus 
Avenue, Tremont Street, and the New York, New Haven and Hart- 
ford Railroad. Most of this interchange would therefore be ele- 
vated, instead of depressed as it is in the Recommended Location. 
Alternate Design I has the same horizontal alignment as the Rec- 
ommended Location in the Southwest Expressway interchange 
area. However, it presents a different horizontal alignment in the 
vicinity of Wentworth Institute and the Museum of Fine Arts than 



does the Recommended Location, which diverges and passes to 
each side of the block bounded by Museum Road, the Fenway, 
Louis Prang Street, and Huntington Avenue. This design maintains 
a narrow median with both roadways side-by-side, and passes 
directly through this block, requiring all structures in the block to 
be demolished. This location remains depressed after passing 
under Brookline Avenue, so as to pass under the Highland Branch 
of the MTA and Beacon Street, where it joins the tunnel crossing 
of the Charles River, Alternate Design I at the river. 

Alternate Design II is the same as the Recommended Location 
with a similar vertical alignment at Beacon Street, except for a 
difference in horizontal alignment in the vicinity of Wentworth 
Institute and the Museum of Fine Arts. This location passes through 
the parking lot of the Museum of Fine Arts, leaving all structures 
in the above-mentioned block intact, but passing very close to the 
Museum. It then connects to the Alternate Design II for the Charles 
River crossing. 

The Alternate Location of the Inner Belt in Boston is along 
Tremont Street and Francis Street. This location begins at the 
southerly end of the Central Artery, passes over Massachusetts 
Avenue and beneath Washington Street at Ruggles Street, just 
north of the Dudley MTA Station. This location becomes parallel 
to Dudley Street as it enters the interchange with the Southwest 
Expressway, located along Washington Street. The interchange is 
planned so as to avoid the First Church in Roxbury at John Elliot 
Square, and the MTA storage and maintenance facilities south of 
Dudley Station. This location then passes over Roxbury Crossing 
and the New York, New Haven & Hartford Railroad, and parallels 
the west side of Tremont Street in a side hill location. At Roxbury 
Crossing, extensive improvements to the surface street system, in- 
cluding a separate underpass of the area for Columbus Avenue 
through-traffic, are necessary in order to handle the traffic move- 
ments effectively. The Alternate Location passes under St. Al- 
phonsus Street and Huntington Avenue between Francis Street and 
Fenwood Road, thence under Brookline Avenue and over Muddy 
River to a location parallel to Kent Street and along the west side 
of Longwood Towers in Brookline. At the intersection of Brookline 
Avenue and The Riverway, extensive facilities are required to pro- 



INNER BELT AND EXPRESSWAY SYSTEM 



V-5 



















TABLE B-l 




































INNER BELT 
































SUMMARY 


OF PHYSICAL EFFECTS 




















OR TOWN: 














NUMBER IN 


CATEGORY 
























Recommer 


ided Location 






Alternate Design 1 

Boston Brookline 


Alternate Design II 




Alternate Location 








CITY 


Boston 


Brookline 


Cambridge 


Somerville 


Boston 




Boston 


Brookline 


Boston 


Brookline 


Cambridge 


Som< 


erville 


Boston 














(Charlestown) 




















(Charlestown) 




CATEGORY 














Totals 




















Totals 


Use of Structures 


































Residential 




534 


21 


501 


197 


10 


1,263 


463 46 


530 


47 


831 


31 


48 




204 


43 


1,157 


Retail 




59 


1 


117 


27 


3 


207 


52 8 


58 


8 


184 


11 


17 




16 


— 


228 


Wholesale 




4 


— 


6 


2 


— 


12 


3 — 


4 


1 


15 


1 


16 




6 


— 


38 


Business 




3 


3 


10 


— 


— 


16 


6 1 


7 


1 


28 


2 


1 




1 


— 


32 


Service 




23 


3 


38 


2 


1 


67 


28 3 


25 


9 


69 


2 


6 




8 


1 


86 


Institutions 




22 


— 


7 


1 


— 


30 


23 — 


24 


— 


29 


1 


6 




1 


— 


37 


Industry 




24 


— 


23 


30 


4 


81 


24 1 


23 


— 


34 


— 


25 




18 


1 


78 


Recreation 




3 


— 


2 


1 


— 


6 


3 — 


3 


— 


2 


1 


— 




1 


— 


4 


Other Data 




































Vacant Lots 




345 


2 


9 


2 


— 


358 


328 2 


324 


9 


276 


4 


1 




1 


1 


283 


Households Displaced 


1,606 


83 


1,541 


589 


28 


3,847 


1,484 173 


1,757 


204 


2,378 


116 


131 




542 


70 


3,237 


Employees Dl 


isplaced 


763 


21 


945 


642 


121 


2,492 


787 30 


768 


37 


1,380 


316 


2,171 




979 


10 


4,856 


Tax Loss* 




$781,210 


$11,204 


$391,100 


$231,080 


$27,210 


$1,441,804 


$899,022 $79,847 


$1,032,076 


$93,219 


$885,270 


$116,151 


$347,904 


$256,504 


$17,080 


$1,622,909 


'Bated on 1961 tax rotes. 





































vide for the interchange of traffic between these two streets and 
the frontage roads of the expressway, as well as the local access 
ramps. After crossing Muddy River, the Alternate Location is in a 
depressed section until it reaches Beacon Street, which it crosses 
on viaduct as it proceeds northerly in a location parallel to and 
east of Amory Street to join with the location of the Charles River 
crossing. 

DESCRIPTION AND ANALYSIS OF 
OTHER LOCATIONS STUDIED 

In addition to the Recommended and Alternate Locations, 
other alternative locations were studied, including many combina- 
tions of interconnections between these alternatives and the Recom- 
mended and Alternate Locations. There follows a brief description 
of two of the alternative locations considered. 

ALTERNATIVE LOCATION A 

This location is completely elevated from the Southwest Ex- 



pressway interchange to Beacon Street, in the same horizontal 
location as Alternate Design II of the Recommended Location. This 
alternative was discarded, because it offered no particular eco- 
nomic advantage over a depressed roadway, as a consequence of 
the poor foundation conditions. 

ALTERNATIVE LOCATION B 

This location is depressed from the Southwest Expressway 
interchange to Beacon Street, and passes west of the Museum 
School and St. John of Damascus Church, with its center-line along 
the center of Louis Prang Street. This location would require ex- 
tensive alteration of major utilities without concurrent advantages 
to offset these additional costs, and was therefore discarded. 

ANALYSIS OF RECOMMENDED AND ALTERNATE LOCATIONS 

TRAFFIC SERVICE 

The Recommended Location in Boston, between Massachusetts 



Avenue and the Charles River crossing, provides fourteen ramps, 
consisting of ten parallel-type ramps to and from the Inner Belt 
and four ramps serving the Southwest Expressway directly. The 
traffic assignments to this section of the Inner Belt reflect major 
desires to and from the north and northwest. To serve these de- 
sires, three on-ramps and three off-ramps are provided. Service 
to the Southwest and Southeast Expressways and the Central Artery 
consists of two on-ramps and two off-ramps. Within the recom- 
mended direct-connector interchange with the Southwest Express- 
way, two off-ramps from the Southwest Expressway are provided 
to serve traffic having destinations inside the Inner Belt. Two south- 
bound on-ramps are provided: one from the frontage road and 
one from Columbus Avenue for the return movement. Direct con- 
nections are provided to the Massachusetts Turnpike, for service 
to and from the western corridor. The Alternate Designs to the 
Recommended Location provide essentially identical traffic service 
to that provided by the Recommended Location. 



V-6 






INNER BELT AND EXPRESSWAY SYSTEM 



An extensive and essential collector-distributor surface road 
system is recommended between Massachusetts Avenue and Beacon 
Street to intercept and distribute the high ramp-volumes to the 
existing arterial streets. To realize the maximum benefits from the 
Inner Belt and Expressway System, these connecting arterial streets 
will require alterations and improvements to increase their opera- 
tional efficiency, in order to accommodate the high-volume ramp 
traffic and the resulting turning movements. 

The Alternate Location provides comparable local inter- 
changes to serve the major traffic desires. Twelve parallel on- and 
off-ramps provide service to the Inner Belt, including eight for 
service to and from the north and west, and four for service to and 
from the south and east. At the direct-connector interchange with 
the Southwest Expressway, intown on- and off-ramp service is pro- 
vided, connecting the Southwest Expressway to Tremont Street and 
Columbus Avenue for trips having origins or destinations in the 
Back Bay and South End. Direct connections to the Massachusetts 
Turnpike are provided prior to crossing the Charles River, for serv- 
ice to and from the west. As with the Recommended Location, a 
continuous collector-distributor surface road system is included as 
shown on the Basic Design Exhibits, between Massachusetts Avenue 
and Commonwealth Avenue, to provide adequate interception and 
distribution of ramp traffic. 

Although the volumes of traffic assigned to the Recommended 
and Alternate Locations of the Inner Belt in Boston and Brookline 
are approximately the same because of corresponding capacity 
limitations, the Recommended Location of the Inner Belt provides 
for superior comprehensive traffic service in Boston and Brookline, 
as compared with the Alternate Location, for the following reasons: 

a. The Recommended Location is closer to the downtown core 
of the city, thereby reducing the length of travel on local 
streets for a greater number of vehicles. 

b. The Recommended Location permits the collector-distribu- 
tor roadways to intercept three more arterial streets than 
does the Alternate Location. 

c. The Recommended Location complements the existing 
street pattern, whereas the Alternate Location crosses 
several major points of existing traffic congestion, and 
its local-access ramps tend to add to this congestion in 



spite of the provision of collector-distributor roads, 
d. The Recommended Location provides a more even distri- 
bution of ramp volumes, which results in less congestion 
of the local street system. 

PHYSICAL AND FUNCTIONAL EFFECTS 

A comparison of the physical effects of the Recommended 
and Alternate Locations and the Alternate Designs to the Recom- 
mended Location in Boston and Brookline is presented in Table B-l. 
This comparison shows that the Recommended Location results in 
far less displacement of families and businesses than the Alternate 
Location. The Recommended Location offers far greater advan- 
tages than the Alternate Location for integration of the Inner Belt 
with present and future land-use developments in both Boston and 
Brookline. Both locations in Boston are within General Neighbor- 
hood Renewal Plan areas of the Boston Redevelopment Authority. 
A major part of the Recommended Location passes through an area 
programmed for clearance, and the balance is either a depressed 
or tunnel section through The Fenway, causing no displacements. 
A major part of the Alternate Location in Boston passes through 
an area programmed for rehabilitation, and its entire length in 
Brookline passes through residential property of very high value. 
In excess of eighty percent of all displacements caused by the 
Recommended Location occur in the Renewal Area between Mas- 
sachusetts Avenue and Columbus Avenue, which is designated for 
clearance, and therefore displacements produced by the Recom- 
mended Location of the Inner Belt would inevitably occur under 
the urban renewal program. In addition, over twenty-two percent 
of all land to be acquired for the Recommended Location in Bos- 
ton and Brookline is presently unimproved and vacant. The Rec- 
ommended Location of the interchange with the Southwest Express- 
way is in an area which contains many abandoned structures 
which have been condemned by the City of Boston. Over ten 
percent of this land has already been acquired by the City of 
Boston through condemnation proceedings, and over thirty per- 
cent of the land is presently vacant. 

For purposes of identification, any structure housing a church 
or religious body has been designated as an institution, and a large 
number of these would be taken by each of the Inner Belt loca- 



tions. However, in the case of the Recommended Location, many 
of these institutions which are being used in whole or part by a 
small group as a church or meeting place, are former stores or 
other commercial-purpose buildings with small replacement value. 
The following institutional-type structures are included among 
those taken by the Recommended Location: St. Francis DeSales 
Church, Roxbury Neighborhood House, Fourth Methodist Episcopal 
Church, St. Cyprian's Episcopal Church, Asa Gray and Sherwin 
Schools, Salvation Army Neighborhood Center on Vernon Street, 
and Massachusetts Society for Prevention of Cruelty to Children 
building on Parker Street. 

The Alternate Designs to the Recommended Location produce 
physical effects similar to the Recommended Location except that: 

a. Alternate Design I requires the displacement of all struc- 
tures in the block bounded by Louis Prang Street, Hunt- 
ington Avenue, Museum Road and The Fenway, and 
therefore results in taking the Museum School, St. John of 
Damascus Church and Parish House, and a large block of 
apartments. This design also includes a tunnel crossing 
of the Charles River for the Inner Belt, and the connec- 
tion of the Massachusetts Turnpike to and from the north 
for the Inner Belt crosses the Charles River on a two-level 
bridge. While this design has some obvious aesthetic 
advantages, as noted later, there is a rather severe cost 
disadvantage. 

b. Alternate Design II results in a minimum of displacements 
in the vicinity of the Museum of Fine Arts, since it passes 
through the Museum parking lot. The interchange with 
the Massachusetts Turnpike is located in Boston and Brook- 
line entirely over land; thus a greater number of struc- 
tures are affected than by the Recommended Location. 

The Alternate Location tends to divide similar present and 
proposed land-use patterns. The Alternate Location interchange 
with the Southwest Expressway is in an area programmed for re- 
habilitation under urban renewal, and some of the structures to 
be taken for the expressway would have been preserved under 
urban renewal. Furthermore, the Alternate Location generally dis- 
rupts this entire area and makes difficult the future development 



INNER BELT AND EXPRESSWAY SYSTEM 



V-7 



of the area under urban renewal. The section of the Alternate Lo- 
cation along Tremont Street occupies valuable property, which has 
been considered ideal for possible future expansion of the hospital 
complex surrounding the Harvard Medical School, and also for 
general business development. 

The Alternate Location in Brookline divides areas of similar 
land use and tends to disrupt future use and development of the 
area. Due to the topography in this area, it would be expensive to 
construct the Alternate Location as a depressed expressway, and 
a considerable increase in the width of taking would be required, 
which accentuates the physical separation of the easterly part of 
Brookline. The Alternate Location would have a decidedly adverse 
effect on the Town of Brookline, both in initial land requirements 
and future development. 

The number of institutional structures taken by the Alternate 
Location is considerable, and includes the Roxbury Neighborhood 
House, Timilty, Dillaway, Bacon, and Davis Schools, a Police and 
Fire Station, St. James Episcopal Church, Boys' Club of Boston, 
Roxbury Court House, Roxbury Post Office, St. Francis DeSales 
Church and School and the Convent on Vernon Street, Deaconess 
Hospital Nurses Home, two buildings of Wheelock College, and St. 
Dominic's Institute in Brookline. 

The total cost of right-of-way acquisition and the total as- 
sessed valuation of property taken are each approximately $5.8 
million less for the Recommended Location than for the Alternate 
Location. The Alternate Location would take $500,000 more in 
tax-exempt property than the Recommended Location. The result- 
ing short-term annual tax loss for Boston and for Brookline is ap- 
proximately $100,000 less in each of these communities for the 
Recommended Location than for the Alternate Location. 

The Recommended Location results in a minimum of disloca- 
tions and disruption of existing land use, and provides maximum 
opportunity for the future development of the area. Between 
Parker Street and Brookline Avenue, the combination of depressed 
and tunnel sections of the Recommended Location preserves the 
integrity of the adjacent institutions. The total impact of the Rec- 
ommended Location on Boston and Brookline is relatively minor, in 
that proposed clearance under urban renewal would result in 



nearly identical physical effects. The over-all effect of the Rec- 
ommended Location on Boston and Brookline would be a consid- 
erable net gain in property values resulting from the functional 
effect of vastly improved accessibility. The Inner Belt in its en- 
tirety will produce an increase in accessibility throughout the 
Metropolitan Area, and although the largest share of the gain in 
property values due to the increased accessibility will accrue to 
Boston, the Town of Brookline will also show substantial gains in 
property values. 

COST ANALYSIS 

The summary of costs of the Recommended and Alternate 
Locations of the Inner Belt are presented in Table B-ll, together 
with a summary of the costs of Alternate Designs I and II for the 
Recommended Location. In addition to this summary, cost data 
was prepared to enable a comparison of costs for those sec- 
tions of the Recommended and Alternate Locations between com- 
mon points. The following costs are presented for the Inner Belt 
from Massachusetts Avenue, Boston, to the Cambridge side of the 
Charles River: 



Recommended 
Location 



Alternate 
Location 



Right-of-Way Costs 
Construction Costs* 

Total Costs 



$ 9,519,000 $15,339,000 
74,664,000 59,705,000 



$84,183,000 $75,044,000 



Including Demolition, Engineering, and Contingencies. 



The Recommended Location in Boston and Brookline would 
cost $15 million more to construct than the Alternate Location in 
Boston and Brookline. The major factor influencing this cost dif- 
ferential is that the Recommended Location is generally depressed 
whereas the Alternate Location is generally elevated. The Recom- 
mended Location is depressed between Washington Street and 
Brookline Avenue, and in the vicinity of the Museum of Fine Arts 
is covered as a tunnel section, due to its close proximity to the 
many fine institutions along Ruggles Street and The Fenway. A 
depressed location would preserve the character of the area and 
maintain its integrity, whereas an elevated location would tend to 



separate the various institutions and detract from their integrated 
function and aesthetic appearance. 

The cost differential between the two locations is further 
accentuated by factors which generally favor an elevated express- 
way along the Alternate Location, and are unfavorable to a de- 
pressed expressway along the Recommended Location. Because 
the Recommended Location is depressed, several large utilities must 
be relocated, at a cost of $2.5 million. The high water-table along 
the Recommended Location requires costly construction methods 
and use of expensive waterproofing materials, whereas the favor- 
able foundation conditions along the Alternate Location result in a 
more economical type of construction, even though considerable 
amounts of rock excavation are involved. 

The cost of construction of the Alternate Designs for the Rec- 
ommended Location is approximately the same as that for the 
Recommended Location, except in the case of Alternate Design I 
between Beacon Street in Boston and Massachusetts Avenue in 
Cambridge, Cost Section No. 3 in Table B-ll. This Design involves 
a tunnel crossing of the Charles River and costs approximately 
$47 million more to construct between these limits than does the 
Recommended Location, primarily due to the greater cost of the 
tunnel, the considerable amount of relocation required for the 
Massachusetts Turnpike, and the large cost associated with pro- 
viding depressed connections to the Turnpike from the Inner Belt 
to the south. 

The cost of acquisition of the right-of-way would be $5.8 
million less for the Recommended Location than for the Alternate 
Location. This difference results from the greater length, and the 
higher density and greater value of structures, along the Alternate 
Location. The assessed valuation of all property in Boston and 
Brookline necessary for the construction of the Recommended Loca- 
tion is $8,002,000 and for the Alternate Location $13,936,000. 

ROAD-USER BENEFIT ANALYSIS 

The results of the road-user benefit analyses, described in 
Part II and applied to the Recommended and Alternate Locations 
of the Inner Belt in Boston and Brookline, are shown in Table B— III- 
The road-user benefit values more than justify the construction of 
either location as economically sound. The road-user benefit ratio 



V-8 



INNER BELT AND EXPRESSWAY SYSTEM 



TABLE B-ll 

INNER BELT 

PROJECT COSTS 

In Thousands of Dollars 




Totals 



$108,495 



RECOMMENDED LOCATION 



$2,624 



$2,645 



$5,224 



$3,950 



$122,938 



$2,969 



$125,907 



$18,886 











Construction Costs £TXUu*Uj 






Demolition 
Cost 


Construction 

Cost Plus 

Demolition 


Engineering 

and 

Contingencies 

$ 3,438 


Right-of-Way 
Costs, 

Total Fair 
Market Value 




Section 
Number 


Structures 


Earthwork 


Pavement 


Utility 
Relocation 


Miscel- 
laneous 


Total 

Construction 

Cost 


Total 
Costs 


1 


$ 18,125 


$1,100 


$ 


713 


$1,075 


$1,003 


$ 22,016 


$ 906 


$ 22,922 


$ 3,233 


$ 29,593 


2 


17,434 


89 




444 


2,743 


1,711 


22,421 


204 


22,625 


3,394 


4,842 


30,861 


3 


27,133 


500 




315 


570 


387 


28,905 


499 


29,404 


4,411 


5,340 


39,155 


4 


3,941 


385 




744 


155 


190 


5,415 


346 


5,761 


864 


3,670 


10,295 


5 


14,886 


510 




389 


180 


469 


16,434 


892 


17,326 


2,599 


5,356 


25,281 


6 


26,976 


40 




40 


501 


190 


27,747 


122 


27,869 


4,180 


1,584 


33,633 



$24,025 



$168,818 



ALTERNATE DESIGN I 



1 


$17,359 


$ 706 


$ 565 


$ 528 


$ 942 


$ 20,100 


$ 851 


$ 


20,951 


$ 4,190 


$ 2,999 


$ 28,140 


2 


21,001 


259 


370 


1,550 


1,328 


24,508 


259 




24,767 


4,953 


6,087 


35,807 


3 


59,863 


783 


388 


2,936 


965 


64,935 


432 




65,367 


13,073 


8,303 


86,743 




$ 23,717 


$ 93 


$ 369 


$2,899 


ALTERNATE 


DESIGN II 


$ 179 


$ 


28,106 


$ 5,621 


$ 5,113 




2 


$ 849 


$ 27,927 


$ 38,840 


3 


28,776 


385 


355 


684 


432 
ALTERNATE 


30,632 
LOCATION 


564 




31,196 


6,239 


7,665 


45,100 


1 


$ 8,472 


$1,645 


$1,056 


$ 935 


$1,460 


$ 13,568 


$1,206 


$ 


14,774 


$ 2,216 


$ 7,173 


$ 24,163 


2 


11,434 


2,797 


720 


487 


446 


15,884 


402 




16,286 


2,443 


4,875 


23,604 


3 


34,994 


346 


299 


772 


536 


36,947 


255 




37,202 


5,580 


7,037 


49,819 


4 


6,923 


13 


43 


153 


81 


7,213 


78 




7,291 


1,094 


2,338 


10,723 


5 


22,312 


93 


203 


113 


343 


23,064 


467 




23,531 


3,530 


4,704 


31,765 


6 


33,120 


18 


125 


122 


331 


33,716 


283 




33,999 


5,100 


2,960 


42,059 



Totals 



$117,255 



$4,912 



$2,446 



$2,582 



$3,197 



$130,392 



$2,691 



$133,083 



$19,963 



$29,087 



$182,133 



COST SECTIONS 

1. Massachusetts Avenue to New York, New Haven & Hartford Railroad 

2. New York, New Haven & Hartford Railroad to Beacon Street 

3. Beacon Street to Massachusetts Avenue, Cambridge 

4. Massachusetts Avenue to Hampshire Street — Recommended Location 
Massachusetts Avenue to Broadway — Alternate Location 

5. Broadway to McGrath Highway 

6. McGrath Highway to Prison Point Bridge 



PROJECT COSTS PER MILE 





Recommended 


Alternate 


Number of Miles 


6.2 




7.2 


Construction and Engineering Cost/Mile 


$23,354 




$21,256 


Right-of-Way Cost/Mile 


$ 3,875 




$ 4,040 


Project Cost/Mile 


$27,229 




$25,296 



INNER BELT AND EXPRESSWAY SYSTEM 



V-9 



indicates a 3.9-to-one economic advantage over travel on the 
existing surface street network for the Recommended Location, as 
compared with a 4.3-to-one economic advantage for the Alternate 
Location. Comparison of the annual road-user benefit values for 
the two locations shows an incremental saving of $1 million annually 
in favor of the Recommended Location. 

LOCATIONS IN CAMBRIDGE, SOMERVILLE, 
AND CHARLESTOWN 

GENERAL 

The Inner Belt locations in Cambridge, Somerville, and 
Charlestown are controlled by the Charles River crossing in the 
vicinity of Boston University Bridge, as previously discussed, and 
by the terminus of a presently-designed section of the Inner Belt 
in the vicinity of Prison Point Bridge in Charlestown, shown as Ter- 
minal Control Point 2 on Exhibit B-l. This is one of the seven ter- 
minal control points previously outlined in Part II. These controls, 
together with the urban structure of the cities, involving densely 
populated and complex land uses, are factors having important 
bearing on the selection of Inner Belt locations. 

The major land-use controls in Cambridge are the Charles 
River recreational area, the industrial complex east of Central 
Square, the Central Square shopping district, the Cambridgeport, 
Donnelly Field and Houghton Renewal Areas, and the commercial, 
educational, and research institutions bordering the Charles River. 
In Somerville, the land-use controls are the heavily industrialized 
areas adjacent to the Boston and Maine Railroad yards and along 
the Fitchburg Division of this railroad. Residential properties inter- 
mixed with light industry occupy the area immediately north of the 
Somerville-Cambridge City Line. This area also includes Lincoln 
Park, a recreational playground for the neighborhood. Between 
Washington Street and Broadway, the land is used predominantly 
for residential purposes. In the Charlestown section of Boston, the 
major land-use controls are the Boston and Maine Railroad yards, 
and the existing and proposed industrial and commercial estab- 
lishments in and around the yards and bordering Rutherford 
Avenue. 



TABLE B-lll 

INNER BELT 

BOSTON-BROOKLINE 

ROAD-USER BENEFIT ANALYSIS 





Recommended 


Alternate 


Item 


Location 


Location 


Length, miles 


2.9 


3.5 


Annual Road-User Benefit 


$19,919,000 


$18,837,000 


Annual Cost of Expressway 


$ 5,103,000 


$ 4,371,000 


Road-User Benefit Ratio 


3.9 


4.3 



The existing street patterns in Cambridge, Somerville, and 
Charlestown are other major considerations in selecting locations 
for the Inner Belt. The collection and distribution of expressway 
traffic must be accomplished by the local street systems. It is im- 
portant that careful consideration be given to the expected change 
in traffic patterns. At the present time there is a heavy volume of 
truck traffic in and through this area, much of which passes di- 
rectly through Central Square. With the construction of the Mas- 
sachusetts Turnpike interchange at Cambridge Street, Allston, and 
the accompanying tandem trailer and flexi-van operations, the 
truck traffic through Central Square will be substantially increased, 
thereby causing greater traffic congestion. This congestion can 
be relieved only by the Inner Belt, which, together with a direct- 
connection interchange with the Massachusetts Turnpike, will permit 
heavy trucking to remain on the Expressway System until a local 
street interchange close to its destination is reached, thereby elim- 
inating extensive truck travel along the surface streets in Cam- 
bridge and Somerville. 

The Northwest and Northern Expressways also influence the 
location of the Inner Belt. The location of the Northwest Express- 
way interchange with the Inner Belt must be compatible with land 
uses, street systems, the corridors for the Expressway, and with 
the interchange between the Northern Expressway and the Inner 
Belt. The Northwest Expressway interchange area is generally 
located within proposed urban renewal areas in Cambridge and 



Somerville. This location provides maximum opportunity for co- 
ordinated urban renewal planning and highway construction, and 
permits adequate spacing between the Northwest and Northern 
Expressway interchanges. 

The Northern Expressway interchange can be located either 
in the Boston and Maine Railroad yards, or between Washington 
Street and Broadway north of the railroad yards. Because this 
interchange area is also located within proposed urban renewal 
areas in Somerville and Charlestown, there is maximum oppor- 
tunity for coordinated planning. The location of the Northern Ex- 
pressway interchange controls the location of the Inner Belt in 
Charlestown. Location of this interchange north of the railroad 
yards allows the Inner Belt to be located over the railroad siding 
parallel to Rutherford Avenue. However, with the location of the 
interchange in the Boston and Maine Railroad yards, the Inner Belt 
must remain in the yards from the Northern Expressway inter- 
change to the end of a presently-designed section of the Inner 
Belt in the vicinity of Prison Point Bridge. 

In the Alternate Location, the Northern Expressway inter- 
change is in the area north of Washington Street, and the North- 
west Expressway interchange is north of Donnelly Field. This 
arrangement provides sufficient spacing between these major inter- 
changes. If the interchange with the Northern Expressway were 
located in the Boston and Maine Railroad yards, as in the Recom- 
mended Location, the interchange with the Northwest Expressway 
would have to be located south of Donnelly Field in order to main- 
tain adequate spacing between the interchanges. Locating the 
Northwest Expressway interchange south of Donnelly Field was 
considered impracticable because of the extensive physical effects 
on Cambridge. 

TOPOGRAPHY AND SUBSURFACE CONDITIONS 

The Recommended and Alternate Locations, located within 
the Boston Basin, have similar general subsurface characteristics 
with only local variations. A relatively shallow surface-layer of 
fill overlies a thin stratum of fine-to-coarse sand, which in turn 
overlies substantial depths of blue clay. The top zone of the clay, 
generally not less than 10 feet in thickness, is desiccated and is 
relatively stiff. A deposit of glacial till varying in thickness is gen- 



V-IO 



NNER BELT AND EXPRESSWAY SYSTEM 



& 



erally encountered below the clay deposit, overlying the bedrock. 
Bedrock rises irregularly but continuously toward the north, from 
depths of approximately 120 feet below the surface at Memorial 
Drive in Cambridge, to within 50 feet of the surface at the Somer- 
ville Line on Webster Avenue. In Somerville, rock continues to rise 
toward the north, approaching to within 10 feet of the ground sur- 
face in the vicinity of Prospect Hill, and then deepening to 30 feet 
in the vicinity of the Northern Expressway interchange. In the area 
to the west and north of the yards, deposits of sand and till gen- 
erally overlie the comparatively shallow bedrock. 

Shallow and localized organic deposits are present in Som- 
erville and along the more easterly alignments in Cambridge. Be- 
neath the shallow surface-fill, soft peat and organic silt deposits, 
averaging five feet in thickness, appear in the central and northern 
sections of the locations along the Grand Junction Branch of the 
New York Central Railroad. 

DESCRIPTION OF RECOMMENDED AND 
ALTERNATE LOCATIONS 

The Recommended Location in Cambridge, after crossing the 
Charles River just west of Boston University Bridge, parallels Brook- 
line Street and crosses Massachusetts Avenue east of Central 
Square. From Massachusetts Avenue, the location continues be- 
tween Columbia and Elm Streets northeasterly to an interchange 
with the Northwest Expressway at the Cambridge-Somerville City 
Line between Donnelly Field, Cambridge, and Lincoln Park, Som- 
erville. In Somerville, the Recommended Location crosses over the 
Fitchburg Division of the Boston and Maine Railroad and McGrath 
Highway, enters the Boston and Maine Railroad yards, and runs 
parallel to Washington Street south of the industrial complex, to 
an interchange with the Northern Expressway at the Somerville- 
Charlestown Line. It then proceeds easterly through the railroad 
yards in Charlestown to the end of a presently-designed section of 
the Inner Belt in the vicinity of Prison Point Bridge, shown as Ter- 
minal Control Point 2 on Exhibit B-l. 

The Alternate Location in Cambridge crosses the Charles River 
just west of Boston University Bridge, and follows the right-of-way 
of the Grand Junction Branch of the New York Central Railroad 



as an elevated double-decked structure. It interchanges with the 
Northwest Expressway north of Donnelly Field and continues across 
McGrath Highway, the Boston and Maine Railroad, and Washing- 
ton Street to an interchange with the Northern Expressway. The 
interchange with the Northern Expressway is located between 
Washington Street and Broadway at the Somerville-Charlestown 
Line. From the Northern Expressway interchange, the Alternate 
Location continues as a double-decked structure over the railroad 
siding which serves the industrial plants along Rutherford Avenue, 
to the end of a presently-designed section of the Inner Belt, shown 
as Terminal Control Point 2 on Exhibit B-l. 

DESCRIPTION AND ANALYSIS OF 
OTHER LOCATIONS STUDIED 

In addition to the Recommended and Alternate Locations, the 
several alternative locations that were investigated in detail are 

described below. 

ALTERNATIVE LOCATION A 

This location, the River Street location, after crossing the 
Charles River continues in Cambridge as an elevated expressway 
across Memorial Drive. From Memorial Drive it continues east of 
and parallel to River Street. At the intersection of Pleasant and 
River Streets this alternative extends easterly, crossing Magazine 
and Pearl Streets, to Massachusetts Avenue at Brookline Street, 
where it becomes common with the Recommended Location. 

This location was one of several presented at the Public Hear- 
ing of May 10, 1960. Its location in Cambridge was controlled by 
the interchange betweeen the Massachusetts Turnpike and the 
Inner Belt within the area of the New York Central Railroad yards 
in Allston. Subsequent to the hearing, the firm decision to extend 
the Turnpike into Boston made this location impracticable because 
of space limitations within the yards, as previously outlined. The 
space required for minimum rail facilities and flexi-van operations 
together with the Turnpike facilities, including an interchange with 
Cambridge Street, precludes the location of an interchange with 
the Inner Belt within the yards as originally studied. Because of 
the space limitations in the railroad yard, all locations along River 



Street in Cambridge were eliminated from further consideration. 
ALTERNATIVE LOCATION B 

This alternative, the Lee Street location, after crossing the 
Charles River in the vicinity of River Street, continues in Cambridge 
as an elevated expressway across Memorial Drive, Putnam and 
River Streets, and Western Avenue. After crossing Western Ave- 
nue, this location continues over Massachusetts Avenue in the 
vicinity of and generally parallel to Lee Street, and thence 
northeasterly between Maple Avenue and Fayette Street, with over- 
passes at Harvard Street, Broadway, Cambridge Street, and Bea- 
con Street. After crossing Beacon Street, the location interchanges 
with the Northwest Expressway between Donnelly Field, Cam- 
bridge, and Lincoln Park, Somerville. From this interchange it con- 
tinues over McGrath Highway and the Boston & Maine Railroad 
where it may become common with either the Recommended or 
Alternate Locations north of McGrath Highway. 

In addition to the space limitations in the New York Central 
Railroad yards, the Lee Street location has the following addi- 
tional disadvantages and was therefore discarded: 

a. This location in Cambridge would pass almost entirely 
through an established residential area, resulting in an 
undesirable division of neighborhoods. 

b. All traffic destined for the major traffic generating sec- 
tions of eastern Cambridge would be forced to travel 
either through local streets, in predominantly residential 
and shopping areas, or through Central Square, a major 
business and shopping center. 

c. Substantial improvements to local streets would be re- 
quired to make an orderly pattern of land use and traf- 
fic distribution in Cambridge. 

d. The location would be incompatible with either existing 
or proposed land uses in Cambridge. 

ALTERNATIVE LOCATION C 

This alternative, the Memorial Drive location, after crossing 
the Charles River in the vicinity of Boston University Bridge, extends 
along Memorial Drive and Commercial Avenue to the present ter- 
minus of the Central Artery. The commercial and educational de- 



INNER BELT AND EXPRESSWAY SYSTEM 



V-l 1 



velopments adjacent to the river create a barrier which precludes 
the connection of the Northwest Expressway directly to the Inner 
Belt Expressway. Therefore, the Northwest Expressway would have 
to be extended along the corridor of the Recommended Location 
of the Inner Belt, in the Boston and Maine Railroad yards, to the 
Northern Expressway, and the resulting combined expressways 
extended to the end of the present design of the Inner Belt. 

The location along Memorial Drive was considered unaccept- 
able and was discarded for the following reasons: 

a. The Inner Belt, in this location, could not properly func- 
tion as a circumferential collector-distributor expressway, 
because a direct connection with the Northwest Express- 
way is impracticable. 

b. Locating the Inner Belt along Memorial Drive would re- 
duce the area of traffic influence of the roadway. An 
expressway located near the centroid of major traffic 
desires would have a greater beneficial influence on local 
traffic patterns, since local traffic would reach the ex- 
pressway from both sides, rather than from only one side, 
as would be the case for the Memorial Drive location. 
The greater the volume of Cambridge traffic that can 
use the expressway with a minimum of travel on local 
streets, the more advantageous the Expressway System 
will be to the City of Cambridge. 

c. Memorial Drive would have to be used as a collector- 
distributor roadway for the Inner Belt; therefore it would 
have to be reclassified to permit trucking. Its use as a col- 
lector-distributor would preclude its functioning as a ma- 
jor arterial supplementing the Expressway System. 

d. By locating the Inner Belt along Memorial Drive, the length 
of the Inner Belt would be decreased, but the length of 
actual roadway required to complete the over-all Express- 
way System would be increased, because extensions of 
the Northern and Northwest Expressways would also be 
required. 

e. This location would greatly reduce the scenic and aesthetic 
attractiveness of the area adjacent to the Charles River, 
and would decrease the value of the river for recreational 



purposes. Since the Charles River Basin is one of the 
major recreational facilities serving the entire Metropoli- 
tan Area, any reduction of its recreational and scenic 
value would be irreparable. 

ALTERNATIVE LOCATION D 

This location, the Donnelly Field location, is common to the 
Recommended Location from the Charles River crossing to Mas- 
sachusetts Avenue. From Massachusetts Avenue this alternative 
extends northeasterly, passing to the east of Donnelly Field, then 
continuing through the Boston and Maine Railroad yards to the end 
of the present design of the Inner Belt, shown as Terminal Control 
Point 2 on Exhibit B-l. 

This location requires that the interchange with the Northwest 
Expressway be located south of Donnelly Field, in order to provide 
sufficient spacing between the Northwest and the Northern Ex- 
pressway interchanges. This Alternative, which is a modification of 
the Recommended Location, precludes the provision of adequate 
traffic service to Somerville and Charlestown, because it is located 
entirely within the railroad yards; it was therefore discarded. 

ANALYSIS OF RECOMMENDED AND 
ALTERNATE LOCATIONS 

TRAFFIC SERVICE 

The Recommended Location in Cambridge, between Memorial 
Drive and the Northwest Expressway, provides two complete local 
street service interchanges. Ramps from the Northwest Expressway 
at the direct-connector interchange with the Inner Belt will permit 
maximum local service to the Cambridge area. Ramps have been 
provided between the Northwest Expressway and McGrath High- 
way to permit direct access to the East Cambridge and North Ter- 
minal areas without requiring travel on the Inner Belt. The limited 
distance betweeen the Northwest and the Northern Expressways 
precludes additional ramps in this area; however, in the vicinity of 
the Northern Expressway interchange, ramps to and from the 
south and west provide traffic service for the Somerville-Charles- 
town area. 

Between Sullivan Square, Charlestown, and Memorial Drive, 
Cambridge, collector-distributor roads are designed to handle the 



assigned ramp volumes adequately, and to permit effective dis- 
tribution to the local arterial streets. In some areas, these collec- 
tor-distributor roads are improved existing streets, widened as 
necessary; in other sections, they are new roadways located adja- 
cent to the Expressway. 

The Inner Belt in the Recommended Location, from the North- 
ern Expressway interchange to its terminus in the vicinity of Prison 
Point Bridge, is a double-decked viaduct. The large traffic desires 
in the Charlestown-Cambridge area for service to and from the 
north are accommodated by parallel ramps to a widened, rebuilt 
Prison Point Bridge. 

The Alternate Location is a double-decked structure for its 
entire length. Two complete diamond-type interchanges are pro- 
vided between Memorial Drive, Cambridge, and the interchange 
with the Northwest Expressway. On- and off-ramps from the 
Northwest Expressway, terminating at the Medford Street-Warren 
Street frontage road system, are provided to serve the northwest 
traffic desires in this area of Cambridge. Ramps are also provided 
between the Northwest Expressway and McGrath Highway, as in 
the Recommended Location. 

Local ramp service in the vicinity of the direct-connector inter- 
change with the Northern Expressway consists of two sets of on- 
and off-ramps, one set serving traffic to and from downtown Bos- 
ton, and the second set serving traffic to and from the south and 
west. A continuous collector-distributor system is also provided in 
the Alternate Location to permit effective distribution of traffic 
between the Expressway and the local arterial streets. 

The Recommended Location of the Inner Belt provides supe- 
rior overall traffic service as compared with the Alternate Location 
for the following reasons: 

a. The Recommended Location is in close proximity to the 
major traffic generators, thereby requiring minimum 
length of travel on local streets. The Alternate Location 
is close to the extremities of the major traffic generators, 
and thus requires longer travel distances on surface 
streets, resulting in greater local street congestion. 

b. The collector-distributor system in the Recommended Lo- 
cation intersects more arterial and local streets than the 



V-12 



NNER BELT AND EXPRESSWAY SYSTEM 






Alternate Location, and permits adequate distribution of 
the assigned ramp traffic. The intersection by the Alter- 
nate Location of only a limited number of roadways will 
increase traffic congestion on the arterial and local streets 
and proposed frontage roads. 

PHYSICAL AND FUNCTIONAL EFFECTS 

A comparison of the physical effects of the Recommended 
and Alternate Locations of the Inner Belt, as summarized in Table 
B-l reveals that the Recommended Location affects more house- 
holds and fewer employees than the Alternate Location. The Rec- 
ommended Location passes through the Cambridgeport and Don- 
nelly Field Renewal Areas in Cambridge, the Linwood-Joy and 
other proposed renewal areas in Somerville, and a proposed re- 
newal area in Charlestown. In reviewing the households affected 
in Cambridge, Somerville, and Charlestown it must be considered 
that many of the householders presently residing in these renewal 
areas will eventually be affected by urban renewal activities, and 
that the tax losses and the numbers of households displaced, jobs 
lost, and businesses affected by the Recommended Location are 
substantially offset by the fact that many of these, recorded in 
Table B-l, would occur under urban renewal activities. 

The City of Cambridge has actively coordinated its renewal 
plans with the expressway location studies to obtain the maximum 
practicable benefits from construction of the Inner Belt. The Rec- 
ommended Location serves as a desirable physical divider between 
the proposed Cambridgeport Renewal Area, which will be pri- 
marily developed for residential purposes, and the existing and 
proposed commercial and industrial areas between the Charles 
River and the corridor of the Recommended Location. Such a 
facility reduces truck traffic filtration through residential neighbor- 
hoods, and provides ready access to the industrial areas. The City 
of Somerville also has planned for future commercial and industrial 
development areas adjacent to the Inner Belt Expressway, thus 
capitalizing on the potential offered by the expressway construc- 
tion through improved access to other sections of the Metropolitan 
Area. Here again, the Inner Belt is planned to act as a buffer 
between existing residential sections and proposed commercial 
and industrial development areas. As shown on Exhibit B-1, a 



major renewal area is generally bounded by McGrath Highway, 
Broadway, and Washington Street. Industrial development is pro- 
posed for the area within these boundaries, located to the east of 
the Expressway, adjacent to the Somerville-Boston City Line and 
Washington Street. There are also other areas located in the 
vicinity of the Expressway System that are proposed for either 
residential, commercial, or industrial development. In Boston, the 
entire Charlestown section has been designated an urban renewal 
area and is presently under study for renewal planning. The area 
within the Boston and Maine Railroad yards is expanding rapidly 
with industrial development and such development is expected to 
be further stimulated by construction of the Inner Belt. 

The Recommended Location is expected to stimulate the re- 
juvenation of the Central Square business area in Cambridge, and 
the proposed and existing commercial and industrial development 
areas in Somerville and Charlestown, by providing convenient ac- 
cess to the Expressway System. Local employment, current renewal 
proposals, and accessibility to other sections of the Metropolitan 
Area provide necessary attractions to sustain these developments. 

The Alternate Location has little effect on the urban structure 
of either Cambridge, Somerville, or Charlestown. The majority of 
the households affected in this location are also located basically 
within proposed renewal areas, many of which, as in the case of 
the Recommended Location, would have been affected anyway 
by urban renewal activities. Since the Alternate Location is essen- 
tially confined to the existing railroad corridor, it displaces fewer 
households than the Recommended Location. However, this loca- 
tion, in order to provide a continuous collector-distributor system, 
does have the disadvantage of disrupting commercial and indus- 
trial activities in Cambridge adjacent to the railroad. The concern 
of city officials to the recent loss of other manufacturing estab- 
lishments is indicative of their probable reaction over the poten- 
tial employment loss resulting from locating the Expressway along 
the railroad. 

Cambridge has recently filed for approval for the expansion 
of the Cambridgeport Renewal Area to include the commercial 
and industrial area between Brookline Street and the railroad, and 
approval would provide additional vitally-needed areas for com- 



mercial and industrial expansion. Since the City is actively en- 
gaged in a program of commercial and industrial expansion, 
the development of transportation advantages, created by the 
Expressway System, will provide a strong and forceful attraction 
for these activities to remain in Cambridge. 

It is possible to exchange the Recommended and Alternate 
Locations of the Northern Expressway interchange with either the 
Recommended or Alternate Locations of the Inner Belt in Cam- 
bridge. However, if the Recommended Location of the Northern 
Expressway interchange is connected to the Alternate Location of 
the Inner Belt in Cambridge, the Northwest Expressway inter- 
change must be located to the south side of Donnelly Field, in 
order to maintain the required spacing between the two directional 
interchanges. By shifting the Northwest Expressway interchange 
to the south of Donnelly Field, a sizable section of Cambridge, 
including the proposed Donnelly Field Renewal Area, would be 
contained between the Somerville City Line and the Northwest 
Expressway. 

Cambridge, Somerville, and Boston are intensely interested 
in the successful completion of their respective renewal programs. 
Early construction of the Inner Belt and Expressway System pre- 
sents an opportunity for these cities to undertake comprehensive 
renewal programs effectively, and to realize their over-all com- 
munity objectives. The structure of the cities will remain essen- 
tially unchanged; however, with several areas rebuilt and local 
street congestion reduced, the opportunities for the successful com- 
pletion of their renewal programs will be greatly improved. 

Vigorous programs of commercial and industrial redevelop- 
ment, coordinated with highway construction, which will provide 
vastly improved access to transportation arteries, will enable these 
cities to compete favorably for their share of the expanding econ- 
omy. Increased access to transportation arteries will also enable 
existing activities to consolidate their competitive positions. Be- 
cause of improved access to a transportation network that will 
link all the major cities in the Boston Metropolitan Area and in the 
United States, land values will increase throughout the entire area 
and in particular in Central Square, in the existing industrial areas 
in East Cambridge, in the area between Brookline Street and the 



INNER BELT AND EXPRESSWAY SYSTEM 



V-13 



New York Central Railroad, in the Boston and Maine Railroad 
yards, in the Sullivan Square area, and along Rutherford Avenue. 
Although an immediate reduction in taxable properties will have 
a temporary effect upon these cities, the currently-planned com- 
prehensive renewal programs, the increased employment result- 
ing from commercial and industrial expansion undertaken in re- 
sponse to these programs, and the increased accessibility afforded 
by the Expressway System, will actually strengthen the communi- 
ties tax bases through more productive and economical use of ex- 
isting land, thereby providing for a better future economic balance. 

COST ANALYSIS 

The summary of costs of the Recommended and Alternate 
Locations of the Inner Belt are presented in Table B-ll. In addi- 
tion to this summary of costs, cost data was prepared to enable 
a comparison of costs for those sections of the Recommended and 
Alternate Locations between their common points. The following 
costs are presented for the northern side of the Charles River to a 
point east of McGrath Highway, where the Recommended and 
Alternate Locations cross, and thence to the Prison Point Bridge, 
at Terminal Control Point 2. 



Summary of Costs: Charles River to Prison Point Bridge 



Charles River to Vicinity of McGrath Highway 



Recommended 
Location 



Alternate 
Location 



Right-of-Way Costs 
Construction Costs* 

Total Costs 



$ 13,206,000 $ 11,305,000 
41,729,000 59,973,000 



$ 54,935,000 $ 71,278,000 



Vicinity of McGrath Highway to Prison Point Bridge 



Recommended 
Location 



Alternate 
Location 



Right-of-Way Costs 
Construction Costs* 

Total Costs 



$ 1 ,300,000 $ 2,443,000 
28,400,000 33,368,000 



$29,700,000 $ 35,811,000 



Recommended 
Location 



Alternate 
Location 



Right-of-Way Costs 
Construction Costs* 

Total Costs 



$ 14,506,000 $ 13,748,000 
70,129,000 93,341,000 



$ 84,635,000 $107,089,000 



The following conditions influence the construction costs of 
the Inner Belt in Cambridge, Somerville, and Charlestown. 

Foundation requirements for the Recommended and Alternate 
Locations present no unusual problems. Since both locations are 
generally within the Boston Basin, where the blue clay deposits are 
prevalent, the costs of the foundations for all structures are based 
upon the use of pile construction, except in the area immediately 
north of Washington Street on the Alternate Location, where soil 
conditions are generally such that spread footings could be used. 

The Recommended Location is designed as an earth embank- 
ment with provision for the planting of shrubs and trees for the 
increased safety of the road users, and to reduce the noise level 
and screen the sight of moving vehicles from the adjacent areas. 
Bridges and viaducts are provided as required to span existing 
streets and railroads which must remain open. That section lo- 
cated within the Boston and Maine Railroad yards is designed as 
a double-decked viaduct. 

The Alternate Location is predicated on constructing the ex- 



TABLE B-IV 

INNER BELT 

CAMBRIDGE-SOMERVILLE-CHARLESTOWN 

ROAD-USER BENEFIT ANALYSIS 



'Including Demolition, Engineering, and Contingencies. 



Item 

Length, miles 
Annual Road-User Benefit 
Annual Cost of Expressway 
Road-User Benefit Ratio 



Recommended Alternate 

Location Location 



3.3 3.7 

$23,964,000 $21,945,000 

$ 4,834,000 $ 6,159,000 

5.0 3.6 



pressway over the Grand Junction Branch of the New York Cen- 
tral Railroad. To accomplish this, a double-decked viaduct is 
necessary for the entire length, from the Charles River to the 
vicinity of Prison Point Bridge. It is also necessary to reconstruct 
the New York Central Railroad trackage from Memorial Drive to 
the Cambridge-Somerville City Line. Long viaduct ramps are re- 
quired to provide service to the top deck, which must be approxi- 
mately sixty feet above existing ground in order to provide for 
rail facilities beneath the viaduct. 

ROAD-USER BENEFIT ANALYSIS 

The road-user benefit analyses for the Recommended and 
Alternate Locations of the Inner Belt in Cambridge, Somerville, and 
Boston (Charlestown) are shown in Table B-IV. The road-user bene- 
fit values more than justify the construction of either the Recom- 
mended or Alternate Locations as economically sound. However, 
the values show an economic advantage in favor of the Recom- 
mended Location. The road-user benefit ratio, which compares 
travel on the new facility to existing street travel, shows a five-to- 
one economic advantage in using the Recommended Location as 
compared with travel on the existing streets. The benefit ratio for 
the Alternate Location shows a 3.6-to-one economic advantage. 
Comparison of the annual road-user benefit values for the two 
locations shows an incremental direct saving in favor of the Rec- 
ommended Location of $2.0 million per year for the road users. 

SUMMARY 

At the present time, the Expressway System for Metropolitan 
Boston is only partially complete and the mass transit system is 
inadequate, and therefore the existing streets and expressways in 
the Core Area do not effectively provide adequate traffic service 
for those who desire to travel into and within the Core Area to 
conduct business, to purchase goods and services, and to attend 
recreational and educational facilities. This traffic must now use 
congested surface streets which pass through high-density com- 
mercial and residential areas, or use expressways already carry- 
ing capacity volumes. The completion of expressway projects 
currently under construction, although part of the Expressway Sys- 



V-14 



INNER BELT AND EXPRESSWAY SYSTEM 



& 



tern, such as the Massachusetts Turnpike, Interstate Route 93, and 
reconstruction of Route 2 to Alewife Brook Parkway, will only 
partially relieve congestion, since for the most part the points of 
congestion will be shifted to new locations until such time as the 
entire Expressway System is completed. The completion of re- 
development projects currently under way, such as the Prudential 
Center, the Government Center, the West End, the New York 
Streets and Linwood-Joy Projects, as well as other renewal projects 
in the planning stage, will attract additional volumes of traffic 
into the Core Area in the near future. Without the completed Ex- 
pressway System, the anticipated increases in population, employ- 
ment and motor-vehicle use will aggravate present problems of 
traffic congestion to the point that many of the traffic generators 
would relocate outside the Core Area to obtain the accessibility 
necessary to maintain their competitive positions. 
^ Completion of the Inner Belt will: 

a. Provide an inter-connection for the Expressway system so 
that the full potential of each radial expressway will be 
realized. 

b. Function as a collector-distributor of traffic in the Core 
Area, and thus deliver traffic close to its destination and 
provide a more even distribution of traffic through the 
Core Area. 



c. Reduce local street traffic, particularly trucks, by removing 
through-travel, thus vastly improving the accessibility and 
environment of business, commercial, industrial and resi- 
dential areas of the core cities. 

d. Provide a stimulus for public redevelopment and private 
development and expansion, by virtue of the tremendous 
economic advantage gained through increased accessi- 
bility. 

e. Increase the real value of all properties, by providing 
ready access to all parts of the Metropolitan Area and 
beyond. 

f. Provide total direct savings in excess of $40 million an- 
nually to those using the Expressway System instead of 

\ existing streets. 

The Recommended Location of the Inner Belt has the following 
advantages as compared with the Alternate Location: 

a. Provides the greater traffic service, because it intercepts 
more arterial streets, and is more centrally located with 
respect to the major traffic generators. Its collector-dis- 
tributor roadways are, in effect, new streets which com- 
plement the existing street network, and the local access 
ramps are more evenly spaced, thus permitting a more 
efficient distribution of traffic. 



b. Creates less disruption of the communities through which 
it passes, and affords greater opportunity for redevelop- 
ment and integration of adjacent land uses with the 
advantages of proximity to the expressway. 

c. Results in the smaller cost of right-of-way and construc- 
tion, displaces fewer structures in all categories except 
residential use, displaces over 2300 fewer employees, 
and results in a smaller total tax loss to the communities 
through which it passes. 

d. Results in a $3 million greater annual benefit to the road- 
user with a smaller annual cost to the taxpayer. 

The Expressway System must be completed promptly to re- 
lieve traffic congestion on the existing streets to permit accessi- 
bility by vehicular travel for those trips which are vital to the 
economic activity of the entire Metropolitan Area. Without an ex- 
pressway system to remove this congestion from the local streets, 
business, commercial and industrial establishments will continue to 
be penalized, commerce and trade will be stifled from traffic 
strangulation, and the economic potential of the Core Area will be 
severely restricted. Full cooperation of public agencies at the 
federal, state, and local levels, and with private enterprise, will be 
required so that the highway construction program recommended 
herein will produce the maximum possible benefits to the Boston 
Metropolitan Area. 




TS.K, 



NNER BELT AND EXPRESSWAY SYSTEM 



V-15 



SECTION 2 - THE SOUTHWEST EXPRESSWAY 



GENERAL 

Interstate Route 95, when completed, will serve the entire 
eastern seaboard with a limited-access expressway from Houlton, 
Maine to Miami, Florida. The Southwest Expressway will be a part 
of this interstate route. The southerly control point at the intersec- 
tion of Route 128 has definitely been established, by previous 
studies, to be just east of the Route 128 Railroad Station at a point 
adjacent to the Neponset River. This is Terminal Control Point 3 of 
the seven terminal control points indicated in Part II and shown 
on Exhibit L-l. The location of the northerly control point, the 
interchange with the Inner Belt, is recommended as a result of 
this Study to be in the lower Roxbury section of Boston between 
Washington Street and Tremont Street at Madison Park. There are 
no adequate existing major thoroughfares connecting these two 
control points of the Southwest Expressway. All streets and thor- 
oughfares which serve this quadrant of the Boston Metropolitan 
Area have either one of two serious limitations as follows: 

a. Narrow, two-lane, heavily congested streets, such as 
Hyde Park Avenue, Washington Street, and Centre 
Street, through high-density residential and commercial 
areas. 

b. Major four-lane thoroughfares which do not offer a con- 
tinuous route into Boston, and which are also used in part 
by traffic moving into Boston from the west. These thor- 
oughfares pass through points of heavy traffic congestion 
or areas of high-density commercial use. Blue Hill Ave- 
nue, Columbia Road, Veterans of Foreign Wars Parkway, 
Jamaicaway, American Legion Highway, Truman Highway 
and Columbus Avenue are examples of thoroughfares in 
this category. 

The main line of the New York, New Haven and Hartford 
Railroad extends in a direct line between these two control points 
and occupies the most favorable connecting natural or topographic 
avenue. The area on each side of the railroad contains many hills, 
abrupt changes in elevation, ledge outcroppings and other difficult 
topographic features which have an important bearing on construc- 
tion costs and consequently on location selection. 



The corridor of study contains numerous large land-use com- 
plexes which have an important bearing on the location of the 
expressway. Major complexes in the area of the Southwest Ex- 
pressway location are the Readville Industrial Area, Geary Square, 
Forest Hills Cemetery, Mount Hope Cemetery, Franklin Park, Arnold 
Arboretum, Notre Dame Academy, New England Hospital for 
Women, Roxbury Crossing, and the business areas around the 
Forest Hills and Dudley Street MTA Stations. 

TOPOGRAPHY AND SUBSURFACE CONDITIONS 

The Southwest Expressway corridor is a shallow trough 
formed by an arm of the Boston Basin at its northern end and the 
Neponset River Valley to the south, separated by a shallow ridge 
approximately midway between Hyde Park and Roslindale. All 
locations studied cross and recross the rim of this trough, resulting 
in marked and rapid changes in subsoil character in both the hori- 
zontal and vertical directions along each alternative location. 
Within the Neponset River flood plain, the soil strata consist typi- 
cally of soft peat, underlain by alluvial sands and silts of varying 
density and thickness. The peat reaches a maximum thickness of 
approximately fifteen feet in some areas of the Neponset Mead- 
ows, but its average thickness is approximately five feet. Total 
depth to bedrock in this valley probably does not exceed thirty 
feet, based upon previously drilled borings. 

In Roslindale, in the area where the alternatives cross Cum- 
mins Highway and reach the southerly extremity of the arm of the 
Boston Basin mentioned above, the overburden generally consists 
of thirty to fifty feet of dense sand and gravel with pockets of 
peat and miscellaneous fill at the surface. The water table is near 
the surface in this area. Excavation of the peat to moderate depths 
will be required where encountered. 

To the east and west of the general axis of the locations 
studied, between Forest Hills and Roxbury Crossing, the topog- 
raphy is dominated by rather steep ridges having a general 
north-south orientation. The northern boundary of these ridges is im- 
mediately south of the Recommended Inner Belt interchange location 
and is formed by the isolated knolls of Washington Park, Highland 
Park and Parker Hill. These knolls mark the edges of the typical 



clay and till deposits of the Boston Basin. Where the bedrock is 
not exposed on these ridges, it is covered with a thin sheet of till. 
In turn, the till is covered in some areas by a sand stratum reaching 
a maximum thickness of about twenty feet. Construction in this 
area will require considerable rock excavation in those cases where 
the expressway profile is established below the existing ground 
surface. 

North of Roxbury Crossing, in the area of the Inner Belt inter- 
change at Madison Park, the typical Boston Basin soils strata are 
encountered. The surface layer consists of miscellaneous fill and 
sand, underlain in turn by various depths of assorted granular ma- 
terials and occasionally trapped pockets of soft peats and silts, 
and then by the blue clay deposit varying in thickness from 50 to 
1 00 feet. The upper layer of this deposit consists of a stiff crust of 
desiccated and weathered clay. Below the clay deposit is glacial 
till laid upon the bedrock floor. As in other locations within the 
Boston Basin, the ground-water table is relatively high, situated 
above the clay deposit. 



LOCATIONS STUDIED 

While numerous locations and combinations of locations for 
the Southwest Expressway were developed to the point where 
clear-cut comparisons could be made, only eight locations merited 
further investigation and development of all factors before a selec- 
tion of the Recommended and Alternate Locations could be made. 
These eight basic locations are shown on Exhibits B-2 and B-3, and 
are referred to hereinafter as follows: 

Recommended Location 
Alternate Location 
Alternative Location A 
Alternative Location B 
Alternative Location C 
Alternative Location D 
Alternative Location E 
Alternative Location F 



V-16 



INNER BELT AND EXPRESSWAY SYSTEM 



e 



DESCRIPTION OF RECOMMENDED AND 
ALTERNATE LOCATIONS 

Major topographic features and large land-use complexes 
are key factors in the selection of locations for the Southwest Ex- 
pressway. The Southwest Expressway from Route 128 northward 
to a point just east of Readville is confined to the valley of the 
Neponset River by the rugged terrain of the Blue Hills and Stony 
Brook Reservations. North of Readville, there are two practicable 
locations, the Recommended and Alternate Locations. 

The Recommended Location extends from the interchange with 
Route 128, Terminal Control Point 3 on Exhibit B-2, northward 
across the Neponset River Reservation to the Neponset Valley 
Parkway, where it turns northwestward to cross the New York, 
New Haven & Hartford Railroad tracks, thence parallels the rail- 
road to a point just south of Roxbury Crossing, where it crosses 
the tracks to the east and passes between Roxbury Crossing and 
Highland Park, thence to the Madison Park interchange with the 
Inner Belt. 

The Alternate Location also extends from the interchange with 
Route 128, and is common with the Recommended Location until 
it is north of the Neponset Valley Parkway, where it crosses the 
Midland Division of the New York, New Haven & Hartford Rail- 
road, and parallels the railroad and the Neponset River until it 
turns northwestward to parallel Huntington Avenue in Hyde Park, 
thence through Barry Quarry to cross Cummins Highway at Ameri- 
can Legion Highway, continuing northwestward until it becomes 
parallel to Hyde Park Avenue, thence continuing to Washington 
Street at Forest Hills. Along Washington Street it is depressed, 
with sufficient space provided in the median for possible rapid 
transit facilities, and at Cedar Street it interchanges with the Alter- 
nate Location for the Inner Belt. 

DESCRIPTION AND ANALYSIS OF OTHER 
LOCATIONS STUDIED 

In addition to the Recommended and Alternate Locations, 
other alternative locations were studied, including many combina- 
tions of interconnections between alternatives. Each of the alter- 
natives can be considered as interchangeable at common points 



of crossing. The following comprises a brief description of the 
locations which were studied and determined to be less advan- 
tageous than the Recommended and Alternate Locations. 

ALTERNATIVE LOCATION A 

Location A crosses the main-line tracks of the New Haven 
Railroad south of Readville instead of north of Readville, and 
therefore parallels the tracks for a greater distance than does the 
Recommended Location. The cost of providing an adequate inter- 
change with the Neponset Valley Parkway is excessive for this 
location. The expressway has to be sufficiently elevated to pass 
over the Parkway which in turn passes over the railroad, thereby 
requiring extensive viaduct construction. The ramps connecting 
to the Parkway could not be located so as to provide adequate 
service, due to the proximity of the railroad and the unusually 
poor alignment of the Parkway. The Westinghouse Electric Com- 
pany Plant is seriously impaired by the loss of its parking facilities 
and railroad siding. Location A was not considered advantageous, 
due to its cost and inferior traffic service, and was therefore dis- 
carded. 

ALTERNATIVE LOCATION B 

Location B utilizes that part of Location A south of the Ne- 
ponset Valley Parkway and then passes west of the Westinghouse 
Plant to rejoin the Recommended Location along the railroad at a 
point west of Cleary Square. This location has some of the 
disadvantages of Location A; however, it does avoid the Westing- 
house Plant. Location B requires the taking of a number of rela- 
tively new homes in order to provide an adequate interchange 
with the Parkway. Additional homes would be taken west of the 
Hyde Park Railroad Station, resulting in a total of approximately 
100 more homes being taken than for the Recommended Location. 
This location was considered unacceptable due to the large number 
of displacements and inferior traffic service, and was therefore 
discarded. 

ALTERNATIVE LOCATION C 

Location C utilizes parts of Locations A and B and continues 
northwestward to by-pass the residential area west of Cleary 
Square. This location does not involve taking as many homes as 



Location B; however, it does pass through a section of the Stony 
Brook Reservation, takes part of the George Wright Municipal Golf 
Course, is immediately adjacent to the Home of the Little Flower 
Orphanage, traverses extremely difficult terrain which would result 
in maximum expressway grades, and requires considerable 
amounts of rock excavation. Adequate connections to existing 
arterial streets could not be made economically, since this location 
would not intercept the street pattern in a favorable location. Loca- 
tion C was considered unacceptable. 

ALTERNATIVE LOCATION D 

Location D leaves the Alternate Location just south of Cum- 
mins Highway and proceeds northward until it becomes common 
with American Legion Highway at the new shopping center. The 
American Legion Highway would be relocated so that it would be 
parallel to and on either side of the expressway to a point just 
south of Morton Street. This location would then proceed north- 
west through Franklin Park, and then northward to pass between 
White Stadium and Walnut Avenue. From this point, Location D 
would pass diagonally through the residential section between 
Walnut Avenue and Washington Street until it became common 
again with the Alternate Location along Washington Street north 
of Columbus Avenue. 

Extensive study and analysis were given this alternative, since 
it results in the most economical location from Cummins Highway 
northward to an interchange with the Inner Belt. However, econ- 
omy is not the sole criterion for selection of the route of an express- 
way, and this location was considered unacceptable and was 
discarded because it: 

a. Passes through the middle of the residential area between 
Calvary Cemetery and the American Legion Highway, re- 
sulting in isolated clusters of residences. 

b. Passes immediately adjacent to the Roslindale General 
Hospital. 

c. Seriously impairs the new shopping center on American 
Legion Highway, requiring the taking of buildings re- 
cently constructed, and materially reducing the capacity 
of the shopping-center parking lot. 

d. Requires the relocation of a number of graves in the 



INNER BELT AND EXPRESSWAY SYSTEM 



V-17 




Exhibit B-2 
SOUTHWEST EXPRESSWAY STUDY LINES — SHEET 1 



V-18 



INNER BELT AND EXPRESSWAY SYSTEM 





LEGEND 



Exhibit B-3 
SOUTHWEST EXPRESSWAY STUDY LINES — SHEET 2 



- - 



SCHOOLS, CHURCHES 

PUBLIC RESERVATIONS, PARKS 

CEMETERIES, COUNTRY CLUBS 
■ ■ ' RAILROADS & TRANSIT LINES 

CITY OR TOWN BOUNDARY LINES 

URBAN RENEWAL AREAS 

GENERAL NEIGHBORHOOD RENEWAL 

PLAN 

PROJECT IN ADVANCE PLANNING 

PROJECT IN EXECUTION 



® Q *$P STATE, U.S., INTERSTATE ROUTES 



& 



W> 



TERMINAL CONTROL POINT 
EXISTING EXPRESSWAYS 
OTHER PROPOSED EXPRESSWAYS 
RECOMMENDED LOCATION 
ALTERNATE LOCATION 

ALTERNATIVE LOCATIONS STUDIED 



1000 



2000 3000 FEET 



SCALE 



CONTOUR INTERVAL 50 FEET 
DATUM IS MEAN SEA LEVEL 



INNER BELT AND EXPRESSWAY SYSTEM 



V-19 



easterly corner of Forest Hills Cemetery, as a result of 
interchanging with Morton Street. 

e. Requires the relocation of a part of the municipal golf 

course on the westerly side of Franklin Park, 
f. Isolates small areas of residential property as it ap- 
proaches Washington Street, and splits land-use patterns. 

g. Requires extensive revisions and additions to the existing 
street system between Morton Street and Columbus Ave- 
nue in order to provide adequate traffic service. 

ALTERNATIVE LOCATION E 

Location E leaves the Recommended Location just south of the 
Forest Hills MTA Station and passes through the westerly edge of 
the Forest Hills Cemetery, through a section which contains main- 
tenance sheds and greenhouses. It then proceeds across the traffic 
circle at the east end of the Forest Hills overpass and becomes 
common with the northerly end of Location D through Franklin Park. 
This location requires a 1500-foot length of 4% grade in order to 
pass over the Forest Hills. It is immediately adjacent to St. An- 
drew's Church on Walk Hill Street, and would seriously affect the 
Forest Hills Cemetery; furthermore, frontage roads are precluded 
for a two-mile length of this location, thereby reducing the effec- 
tiveness of the facility in realizing its full potential. Location E was 
considered unacceptable. 

ALTERNATIVE LOCATION F 

Location F leaves the Recommended Location south of the 
Forest Hills MTA Station, passes through the Arnold Arboretum, 
and rejoins the Recommended Location north of the Forest Hills 
overpass. Location F was developed with a partial cloverleaf-type 
interchange at the Arborway, so as to provide full service to and 
from downtown Boston; however, traffic service to and from the 
south could not be provided economically. This location passes 
through a section of Arnold Arboretum and through two resi- 
dential sections which contain many homes. The resulting separa- 
tion of these residential areas is such as to render the areas subject 
to deterioration, due to the influence of the adjacent business sec- 
tion with which this location groups them. 

Location F does not improve the local traffic condition at 



\ 



Forest Hills, and adversely affects the general area. The partial 
ramp service seriously curtails traffic service to the area and re- 
duces the effectiveness and the potential of the MTA rapid transit 
facilities. Location F was considered unacceptable and was dis- 
carded. 

• ••••• 

Locations G, H, J, and K, as shown on Exhibit B-3, were de- 
veloped to provide connections between sections of the previously 
mentioned alternatives and parts of the Recommended or Alter- 
nate Location, and these locations were considered unacceptable 
due to the disadvantages of the alternatives with which each 
connects. 

ANALYSIS OF RECOMMENDED AND 
ALTERNATE LOCATIONS 

TRAFFIC SERVICE 

The Recommended Location of the Southwest Expressway 
provides five local-service interchanges at the following major 
streets and thoroughfares: 

a. Neponset Valley Parkway 

b. West Street 

c. Cummins Highway 

d. Arborway — Morton Street 

e. Columbus Avenue — Centre Street 

The areas served by these interchanges include Readville, 
Hyde Park, sections of East Dedham and Milton, Clarendon Hills, 
Mattapan, Roslindale, West Roxbury, Mt. Hope, Jamaica Plain, 
Forest Hills, Franklin Park, Roxbury and sections of Dorchester. 
The interchanges permit all eight turning movements at each loca- 
tion either by semi-direct, loop or parallel-type ramps. Extensive 
revisions to the local street pattern, as shown on the Basic Design 
Exhibits, are incorporated at the Cummins Highway, Arborway 
and Columbus Avenue interchanges to serve the assigned ramp 
traffic, and to permit the adequate distribution of this traffic to 
the major arterials. Continuous collector-distributor roadways are 
provided from the Arborway interchange to the Inner Belt, to 
augment the existing street system in the collection and distribution 
of traffic to and from the ramps of the Expressway. 



The Alternate Location provides comparable local service to 
the same major streets listed for the Recommended Locations, as 
shown on the Basic Design Exhibits. The Neponset Valley Parkway 
interchange is identical for both the Recommended and Alternate 
Locations. The remaining four interchanges provide complete turn- 
ing movements for the major streets by either semi-direct, loop or 
parallel-type ramps. Extensive revisions to the local street system 
are required at all four interchange locations, to facilitate ramp 
traffic collection and distribution to the major streets, and to pro- 
vide adequate connections to the local street pattern. Continuous 
collector-distributor roadways are provided from Forest Hills to 
the Inner Belt collector-distributor system. The Alternate Location 
north of Forest Hills provides for possible relocation of rapid 
transit within the Expressway median to replace the present ele- 
vated transit service on Washington Street. 

PHYSICAL AND FUNCTIONAL EFFECTS 

A comparison of the physical effects of the Recommended 
and Alternate Locations for the Southwest Expressway reveals 
that they are similar as far as numerical effect is concerned. 
However, the Recommended Location has decided advantages 
over the Alternate Location in relation to integration of the South- 
west Expressway with present and future land use and effective 
mass transit for the area. 

The Recommended Location parallels the New York, New 
Haven & Hartford Railroad for practically the entire distance 
from Route 128 to the Inner Belt, and would cause a minimum of 
disturbance of the land-use pattern of the area. The Alternate 
Location requires a separate path for its entire length and there- 
fore tends to split similar land-use patterns. Between Forest Hills 
and Dudley Street, the Alternate Location results in isolation of a 
relatively small area between rail and highway facilities, and this 
will seriously restrict redevelopment of this area. 

Both the Recommended and Alternate Locations consider in- 
tegration of rapid transit facilities with the Expressway. The Al- 
ternate Location, between Forest Hills and Dudley Street, assumes 
that the present MTA elevated tracks would be demolished and 
the tracks relocated in the median of the depressed Expressway; 



V-20 



INNER BELT AND EXPRESSWAY SYSTEM 



<<s 



£*ab1 



the MTA station at Forest Hills would be replaced. Sufficient 
right-of-way is included to allow a 50-foot reservation in the 
median for the rapid transit tracks and stations, although no al- 
lowance is included in the construction cost for rapid transit 
facilities. 

It would be possible to utilize the main-line tracks of the 
New York, New Haven & Hartford Railroad to Route 128 Station 
for rapid transit, with a line to Dsdham on the Dover Branch. The 
Midland Division of the New York, New Haven & Hartford Rail- 
road could be utilized for freight service into the South Station 
yards. If this, or a similar plan for rapid transit which utilized 
the railroad right-of-way, could be effected at the time of con- 
struction of the Southwest Expressway, the three media of trans- 
portation could then be combined in one right-of-way. The 
Recommended Location would then provide maximum flexibility 
in redevelopment of the area between Forest Hills and Roxbury 
Crossing, since one combined transportation artery would traverse 
the area, instead of two separate arteries. 

The interchange of the Recommended Location with the Inner 
Belt is approximately one-half mile closer to downtown Boston, 
thereby permitting the Expressway to serve more efficiently its 
function of providing traffic service for the downtown area. While 
this factor places the Inner Belt in a more favorable location from 
a traffic service standpoint, it results in a greater length for the 
Southwest Expressway, a factor which tends to increase the 
physical effects associated with the Recommended Location as 
compared with those of the Alternate Location. The physical 
effects associated with the Inner Belt, however, strongly favor the 
Recommended Location over the Alternate Location, and must be 
considered in the over-all analysis of the choice of the most ad- 
vantageous location of the interchange. 

The Recommended Location involves the taking of approxi- 
mately 100 fewer residential structures than does the Alternate 
Location, even though its connection to the Recommended Location 
of the Inner Belt makes it longer. The total cost of the right-of-way 
taking is less for the Recommended Location than for the Alternate 
Location. The assessed valuation of all property taken by the 
Recommended Location is $8,409,000, and by the Alternate Loca- 



TABLE B-V 

SOUTHWEST EXPRESSWAY 

SUMMARY OF PHYSICAL EFFECTS 

NUMBER IN CATEGORY 



Recommended Location 



CITY OR TOWN: 
CATEGORY 

Use of Structures 
Residential 
Retail 
Wholesale 
Business 
Service 
Institutions 
Industry 
Recreation 

Other Data 
Vacant Lots 
Households Displaced 
Employees Displaced 

Tax Loss* 



Canton 



Milton 



Boston 



$16,925 



ised on 1961 lax rates. 



tion, $10,018,000. However, the Alternate Location involves the 
taking of $2,200,000 more tax-exempt property than does the 
Recommended Location. Therefore, the Recommended Location 
results in a $63,000 greater annual tax loss to the City of Boston 
than the Alternate Location. 

Most of the tax-exempt property taken by the Alternate 
Location involves MTA facilities at Forest Hills, which are valued at 
almost $2,000,000 and would have to be replaced. The Alter- 
nate Location also requires the taking of two public schools. The 
balance of the tax-exempt property taken by the Alternate Loca- 
tion, and the bulk of the tax-exempt property taken by the 
Recommended Location, are the M.D.C. lands of the Neponset 
River Reservation, which is predominantly marsh land. 

Listed in Table B-V are the various categories of property 
which are affected by the respective expressway locations. As 
noted, the number of retail, wholesale, business, service and insti- 
tutional establishments affected by each location is generally the 



Alternate Location 



Canton 



Milton 



Boston 



Totals 



Totals 



— 


823 


823 


— 


95 


95 


— 


1 


1 


— 


12 


12 


— 


54 


54 


— 


3 


3 


— 


47 


47 


1 


7 


9 


, 


291 


292 


— 


2,106 


2,106 


— 


1,178 


1,178 


Public Lands 


$716,352 


$733,277 



— 


925 


925 


— 


84 


84 


— 


1 


1 


— 


9 


9 


— 


55 


55 


— 


4 


4 


— 


21 


21 


1 


7 


9 


_ 


297 


298 


— 


2,168 


2,168 


— 


940 


940 


Public Lands 


$653,196 


$670,121 



$16,925 



same. Although the number of industries affected by the Recom- 
mended Location is twice as great as that affected by the Alternate 
Location, the number of employees displaced is only slightly greater, 
since many of the industries affected by the Recommended Loca- 
tion employ only a few employees each. Approximately 40% of 
all land which would be taken for either location is vacant. 

The Recommended Location, for the most part, takes marginal 
property which presently abuts the railroad right-of-way. In the 
area between Readville and Roxbury Crossing it acts as a buffer 
between the residential section and the railroad. The Alternate 
Location disrupts the residential community off River Street, another 
between Hyde Park Avenue and American Legion Highway, and 
the business section at Forest Hills. 

These physical effects on the economy of Boston are short- 
term. The functional effect of the Southwest Expressway will be 
such as to provide vastly improved accessibility to the Jamaica 
Plain, Roslindale, and Hyde Park sections of Boston. This greater 



INNER BELT AND EXPRESSWAY SYSTEM 



V-21 



Totals 



$ 27,593 



TABLE B-VI 

SOUTHWEST EXPRESSWAY 

PROJECT COSTS 

In Thousands of Dollars 
RECOMMENDED LOCATION 



$6,094 



$3,563 



$1,209 



$2,593 



$ 41,052 



$ 944 



$ 41,996 



$ 6,300 









Con 


struction Costs 














Right-of-Way 


























Costs, 


















Total 




Construction 


Engineering 






Section 








Utility 


Mi 


iscel- 


Construction 


Demolition 


Cost Plus 


and 


Total Fair 


Total 


Number 


Structures 


Earthwork 


Pavement 


Relocation 


laneous 


Cost 


Cost 


Demolition 


Contingencies 


Market Value 


Costs 


1 


$ 2,586 


$ 554 


$ 275 


$ 189 


$ 


189 


$ 3,793 


$ 273 


$ 4,066 


$ 610 


$ 1,592 


$ 6,268 


2 


7,711 


1,128 


806 


454 




517 


10,616 


329 


10,945 


1,642 


4,414 


17,001 


3 


9,580 


833 


563 


197 




597 


11,770 


159 


11,929 


1,789 


3,781 


17,499 


4 


6,197 


933 


1,062 


305 




734 


9,231 


170 


9,401 


1,410 


4,509 


15,320 


5 


1,173 


1,355 


406 


64 




266 


3,264 


13 


3,277 


492 


782 


4,551 


6 


346 


1,291 


451 


— 




290 


2,378 


— 


2,378 


357 


1,014 


3,749 



$16,092 



$ 64,388 



Totals 



$ 15,990 



ALTERNATE LOCATION 



1 


$ 940 


$1,454 


$ 365 


$ 154 


$ 201 


$ 3,114 


$ 212 


$ 3,326 


$ 499 


$ 2,121 


$ 5,946 


2 


5,499 


2,683 


667 


313 


510 


9,672 


248 


9,920 


1,488 


3,799 


15,207 


3 


4,646 


2,892 


709 


215 


491 


8,953 


290 


9,243 


1,386 


5,886 


16,515 


4 


3,386 


2,240 


1,019 


355 


780 


7,780 


157 


7,937 


1,191 


J 3,270 


12,398 


5 


1,173 


1,355 


406 


64 


266 


3,264 


13 


3,277 


492 


782 


4,551 


6 


346 


1,291 


451 


— 


290 


2,378 


— 


2,378 


357 


1,014 


3,749 



$11,915 



$3,617 



$ 1,101 



$2,538 



$ 35,161 



$ 920 



$ 36,081 



$ 5,413 



$16,872 



$ 58,366 



COST SECTIONS 

1. Linden Park Street to Columbus Avenue — Recommended Location 
Kingsbury Street to Columbus Avenue — Alternate Location 

2. Columbus Avenue to Arborway-Morton Street 

3. Arborway-Morton Street to Cummins Highway 

4. Cummins Highway to New York, New Haven & Hartford Railroad 

5. New York, New Haven & Hartford Railroad to Town Lines (Boston-Milton) 

6. Town Lines (Boston-Milton) to Route 128 



PROJECT COSTS PER MILE 



Recommended Alternate 



Number of Miles 


8.7 


8.4 


Construction and Engineering Cost/Mile 


$5,551 


$4,940 


Right-of-Way Cost/Mile 


$1,850 


$2,008 


Project Cost/Mile 


$7,401 


$6,948 



accessibility will result in increased properly values as new in- 
dustries take advantage of the proximity to the downtown Boston 
area. The area east of the railroad between Roxbury Crossing and 
Forest Hills is predominantly industrial in character at present, 
and the resulting improvement in accessibility will provide the 
impetus for its expansion. The area south of Forest Hills will be- 



come readily accessible to all parts of Metropolitan Boston by 
virtue of the Expressway, and its desirability as a residential 
neighborhood will increase together with property values. The 
net effect of the Expressway several years after completion will 
be to increase the tax base of Boston sufficiently to offset the 
initial loss resulting from the displaced properties. 



COST ANALYSIS 

The summary of costs of the Recommended and Alternate 
Locations of the Southwest Expressway is presented in Table B-VI. 
Supplementing the description given in Part II of the general factors 
affecting costs, the following features influence the construction 
costs of the Southwest Expressway. 



V-22 



INNER BELT AND EXPRESSWAY SYSTEM 



The cost of the foundations for the structures of the South- 
west Expressway are based on the use of piles in the area between 
Route 128 and Forest Hills, and spread footings in the area north 
of Forest Hills. The construction cost of the Expressway through 
the Neponset River Reservation is based on removal of the peat and 
replacement with granular material. The Recommended Location 
requires 9,000 feet of viaduct as opposed to 3,000 feet of viaduct 
required for the Alternate Location. The Recommended Location 
requires the relocation of 2,300 feet of the New York, New Haven 
& Hartford Railroad south of Forest Hills. The Alternate Location 
requires the relocation of 2,000 feet of the Neponset River, and 
also requires the extensive use of retaining walls for the depressed 
roadway between Forest Hills and Kingsbury Street. Both Locations 
require extensive local street improvements at Forest Hills in order 
to provide adequate facilities for local service to the Expressway. 

ROAD-USER BENEFIT ANALYSIS 

The results of the road-user benefit analyses described in 
Part II and applied to the Recommended and Alternate Locations 
of the Southwest Expressway are shown in Table B-VII. The annual 
road-user benefit values more than justify the construction of either 
location as economically sound. The values show an economic ad- 
vantage in favor of the Recommended Location of approximately 
$1.1 million annually, primarily because the Recommended Loca- 
tion is a more direct route than the Alternate Location. The road- 
user benefit ratio, which compares travel on the new facility to 
existing street travel, indicates a 4.3-to-one economic advantage 
by the use of the expressway as compared with existing streets. 

SUMMARY 

Interstate Route 95 is one of the major highways of the Inter- 
state System connecting the major urban areas along the Atlantic 
seaboard. Two sections in Massachusetts are completed: the 
Central Artery-Northeast Expressway from Massachusetts Avenue, 
Boston, to Cutler Circle in Revere, and from Danvers to the New 
Hampshire State Line. 1-95 is under construction or in various 
stages of design from the Rhode Island State Line to Route 128. 
The Southwest Expressway forms that part of Interstate Route 95 

INNER BELT AND EXPRESSWAY SYSTEM 



TABLE B-VII 

SOUTHWEST EXPRESSWAY 

ROAD-USER BENEFIT ANALYSIS 





Recommended 


Alternate 


Item 


Location 


Location 


Length, miles 


8.7 


8.4 


Annual Road-User Benefit 


$14,290,000 


$13,227,000 


Annual Cost of Expressway 


$ 3,308,000 


$ 3,233,000 


Road-User Benefit Ratio 


4.3 


4.1 



from Route 128 northward to the Inner Belt, which connects with 
the southerly terminus of the completed segment of 1-95 in Boston. 
In addition to being a part of one of the major interstate highways, 
the Southwest Expressway, as one of the radials of the Expressway 
System, serves the entire southwest quadrant of the Boston Metro- 
politan Area. The existing system of arterial streets and thorough- 
fares in this quadrant of the Metropolitan Area is grossly inadequate 
to satisfy the demands of even present day use; it is heavily 
congested and does not provide a direct route into downtown 
Boston. Lack of accessibility for this area is evidenced by the fact 
that the southwest quadrant of Boston has received far less than 
its proportionate share of new development, and that a large 
volume of traffic with origins in the Canton, Dedham, Norwood and 
Westwood area is presently using the Southeast Expressway for 
travel to downtown Boston. 

Construction of the Southwest Expressway in the Recom- 
mended Location will: 

a. Provide the most direct route from Route 128 to the 
Inner Belt, provide the highest degree of traffic service for 
the Jamaica Plain, Roslindale and Hyde Park sections of 
Boston, provide efficient service to those areas on both 
sides of the New York, New Haven and Hartford Rail- 
road tracks, and the collector-distributor roadway pro- 
vides an even distribution of traffic to the existing street 
system. 

b. Afford far greater opportunity for integration of the 
several modes of transportation in one corridor, and 



concurrently provide the greatest potential for future re- 
development of the area. 

c. Result in displacement of fewer residential structures and 
households, and lower cost of right-of-way acquisition 
than the Alternate Location. In consideration of the ad- 
vantage of the location of the interchange with the Inner 
Belt, one-half mile closer to downtown Boston, the sum of 
the physical effects favor the Recommended Location. 

d. Provide over $1 million greater direct annual benefit to 
the road users than will the Alternate Location. 

The completion of Interstate Route 95 in its entirety is vital to 
the economy and defense capability of the entire New England 
Area, since it serves as the major highway transportation artery 
for the eastern seaboard. The Southwest Expressway, being an 
integral part of this major highway, will be a prime factor in com- 
mercial, industrial and residential development of the southwest 
sector of Boston and adjacent communities. With the through- 
traffic diverted from the existing arterial street system, the sub- 
stantially increased accessibility to all parts of New England will 
enable the southwest sector to realize its economic potential and 
to assume its rightful share in the future growth of the Boston 
Metropolitan Area. 





V-23 



SECTION 3 -THE ROUTE 3 EXPRESSWAY 



GENERAL 

Route 3, one of the major north-south routes of the Federal- 
Aid Primary Highway System, has been essentially completed from 
the New Hampshire State Line to Route 128 in Burlington. To 
complete this facility, an extension must be made southerly from 
Route 128 to integrate with the Expressway System. The Route 3 
Expressway will then become a major traffic distributor for the 
northwest sector of the Boston Metropolitan Area. In order to 
provide optimum traffic service in this sector, the expressway must 
be located so that it will relieve the local street systems in Arling- 
ton, Belmont, Lexington, Winchester, and Woburn, of heavy com- 
mercial and commuting traffic. 

The northerly control point for this Expressway, shown as 
Terminal Control Point 5 on Exhibit L-l, is established by the exist- 
ing cloverleaf interchange with Route 128 in Burlington. This is 
one of the seven terminal control points outlined in Part II. The 
locations of the southerly control points have been determined, as 
a result of this Study, to be either a connection to the Northwest 
Expressway, in the vicinity of Alewife Brook Parkway in North 
Combridge, or a connection to both the Northern Expressway at 
Main Street, Medford, and the Northwest Expressway. 

TOPOGRAPHY AND SUBSURFACE CONDITIONS 

Some of the major topographic controls which influence the 
locations of the Route 3 Expressway are the Great Meadows, the 
Mystic Lakes, the Arlington Reservoir, and Spy Pond. The wide 
corridor for the location studies of Route 3 passes through three 
geologically separate areas as described herein. Topographic 
maps of the area northwest of Boston show a ridge to the west of 
Belmont Center that extends northeasterly, past the northwest side 
of Spy Pond, approximately to Arlington Center, then northerly, 
passing around the Mystic Lakes, and then easterly, parallel to the 
Mystic Valley Parkway. This ridge is the northwesterly rim of the 
Boston Basin, at which the subsurface soil conditions change 
markedly from the typical Boston Basin deposits to the frequent 
bedrock outcropping and irregular glacial till formations of the 
uplands. The mantle of till over the bedrock varies up to ten feet 
in thickness. Within the valley in this area, the depth of the till 



deposit increases, and is often overlain with sands and silts of 
alluvial and fluvio-glacial origin. Construction in this area may re- 
quire considerable rock excavation. 

In the lowlands below this ridge, south of the Alewife Brook 
Parkway, the Expressway follows approximately within the Mystic 
River flood plain. Except for the alluvial sands of the flood plain, 
the soils consist of the typical deposits of the Boston Basin, usually 
overlain by granular soils and fill. The clay becomes increasingly 
deep toward Alewife Brook Parkway, reaching a depth of 50 to 
100 feet in the vicinity of the intersection of existing Route 2 and 
the Parkway, but is somewhat shallower, 30 to 60 feet, at the north- 
erly end of the Parkway. The section of Alewife Brook Parkway 
from existing Route 2 to the intersection with the Mystic Valley 
Parkway lies entirely within the Boston Basin. In the vicinity of 
Route 2 and Alewife Brook Parkway considerable filled land is also 
present, trapping pockets of soft peats and organic silts beneath 
the fill material. The depth to bedrock in this area is quite erratic, 
but is expected to be over 100 feet. Near the rim of the Basin, 
the clay is also shallow but appears to be more sandy, and the 
desiccated upper clay crust is thicker. 

North of the ridge, all locations converging on the existing 
interchange at Route 128 traverse a relatively flat area. The sub- 
surface deposits in this area consist of a mixture of randomly de- 
posited granular soils overlying the relatively impermeable till. In 
this area the water table is relatively high, resulting in a surface 
condition of localized marshes and swamps. The lower areas, Lex- 
ington's Great Meadows, for example, have accumulated a sur- 
face layer of peat which is seldom more than a few feet thick. 



LOCATIONS STUDIED 

The several locations for Route 3 which were studied, before 
a selection of the Recommended and Alternate Locations was 
made, are shown on Exhibits B-4 and B-5 and are referred to here- 
inafter as follows: 

Recommended Location: Great Meadows — Route 2 location. 

Alternate Location: Hutchinson Road — Mystic Valley — Ale- 
wife Brook Parkway location. 



Alternative Location A: Morningside location. 
Alternative Location B: Cambridge Street — Mystic Lakes loca- 
tion. 
Alternative Location C: Railroad location- 
Alternative Location D: Belmont location. 
Alternative Location E: Mystic Lakes — Railroad location. 
Alternative Location F: East Arlington location. 
Alternative Location G: Summer Street location. 

DESCRIPTION OF RECOMMENDED AND 
ALTERNATE LOCATIONS 

The Recommended Location extends southerly from the exist- 
ing interchange with Route 128, shown as Terminal Control Point 
5, and passes through the Great Meadows in Lexington, to exist- 
ing Route 2 at a point near the Arlington-Lexington Town Line. It 
then extends along existing Route 2 to the Recommended Location 
of the Northwest Expressway in the vicinity of Alewife Brook Park- 
way in North Cambridge. 

The Alternate Location extends southeasterly from the exist- 
ing interchange at Route 128 parallel to the Lexington Town Line, 
and passes between the Upper and Lower Mystic Lakes to the 
Mystic River. It then follows the Mystic River Valley to Alewife 
Brook Parkway, where it interchanges with a connector located 
along Alewife Brook and Mystic Valley Parkways between the 
Northwest Expressway, in North Cambridge, and the Northern Ex- 
pressway, in Medford. 

Reference should be made to the Basic Design Exhibits for 
the Recommended and Alternate Locations. 

DESCRIPTION AND ANALYSIS OF 
OTHER LOCATIONS STUDIED 

In addition to the Recommended and Alternate Locations, 
other alternative locations that were studied and determined to be 
less advantageous are described below. 

ALTERNATIVE LOCATION A 

This location begins at the existing interchange on Route 128, 
and is common to the Alternate Location to Johnson Road, Win- 
chester. From Johnson Road, Location A extends southerly, passing 



V-24 



INNER BELT AND EXPRESSWAY SYSTEM 



through the Morningside section of Arlington and across the south- 
ern end of the Lower Mystic Lake to the Mystic River Valley, where 
it again becomes common to the Alternate Location. 

When the Morningside location was first considered, there 
existed an open corridor in which an expressway could be con- 
structed. Since that time, however, high-value residential construc- 
tion has proceeded at a very rapid pace, effectively blocking this 
corridor. Within the past year at least 200 residences have been 
constructed in this area. While Alternative Location A has steep 
gradients similar to the other alternatives, a crossing of the south- 
erly end of the Lower Mystic Lake would be more costly and 
difficult than a crossing between the lakes, as in the Alternate Loca- 
tion, because of the depth of the lake at the mouth of the Mystic 
River. This alternative offers no advantages over the Alternate 
Location, and has the disadvantage of passing through a highly 
developed, attractive and rapidly expanding residential neighbor- 
hood. This location was therefore considered unacceptable and 
thus was discarded. 

ALTERNATIVE LOCATION B 

Alternative Location B extends southeasterly from the existing 
interchange at Route 128 to the Woburn-Winchester Town Line 
near existing Route 3. From this point it extends southerly and 
parallel to existing Route 3, crosses the Upper Mystic Lake, and 
follows the Mystic Valley Parkway to the Mystic River Valley, where 
it becomes common to the Alternate Location. 

Since this location is more easterly than all other locations 
considered, it provides the least service to the Arlington and Lex- 
ington areas, the major traffic generators in this sector. Several 
other disadvantages of this location include the passage through 
extensive residential areas, and considerable reduction of the 
recreational value of the Mystic Lakes, particularly the complete 
disruption of the Metropolitan District Commission Beach Reserva- 
tion. As with Alternative Location A, this location offers no mate- 
rial advantages over the Alternate Location and provides only 
limited traffic service for the major traffic generating areas. This 
location was also considered unacceptable and therefore was dis- 
carded. 



ALTERNATIVE LOCATION C 

Location C is common to the Recommended Location southerly 
from Route 128 to the Boston & Maine Railroad in East Lexington. 
It then extends along the railroad through Arlington Center to exist- 
ing Route 2 in the vicinity of Alewife Brook Parkway in North 
Cambridge. 

Although construction of this alternative would improve con- 
ditions on some of the local streets in Arlington, through elimina- 
tion of railroad grade-crossings and improved grade separations, 
it was discarded because its construction would require complete 
abandonment of the railroad. The inadequacy of the existing 
street network to provide local traffic service, and the physical 
effect on a recently-constructed Old Age Housing Project, as well 
as several athletic fields, parks, and industries adjacent to the 
railroad, are other disadvantages of this alternative. Furthermore, 
the converging of Alewife Brook Parkway, Route 2, the Northwest 
Expressway and Route 3 in the same general area precludes the 
construction of an interchange which would provide adequate serv- 
ice for all of these roadways. 



ALTERNATIVE LOCATION D 

This Alternative is also common to the Recommended Location 
from the Route 128 interchange to the Concord Turnpike. From 
this point it continues over the Turnpike and Concord Avenue, turns 
southeasterly parallel to Concord Avenue, passes to the north of 
the McLean Hospital, crosses over Belmont Hill, crosses Pleasant 
Street (Route 60), and the Boston & Maine Railroad, and then fol- 
lows the railroad to Alewife Brook Parkway in North Cambridge. 

In addition to the disadvantage of long, steep gradients re- 
quired to cross Belmont Hill, this location is much longer than other 
alternatives, creates serious interchanging problems, disrupts busi- 
ness and traffic movements in Belmont Center, passes through the 
Belmont Country Club and the High School Athletic Field, and dis- 
places several commercial establishments adjacent to the railroad 
in Belmont and in Cambridge. For these reasons, this alternative 
was considered unacceptable and therefore was also discarded. 



ALTERNATIVE LOCATION E 

Location E is common to the Alternate Location to a point be- 
tween the Upper and Lower Mystic Lakes. From this point it con- 
tinues across the lakes and extends along the Boston & Maine 
Railroad to the Mystic River, where it interchanges with a connector 
between the Northwest Expressway and the Northern Expressway. 
As compared to other locations along the Mystic River Valley, this 
location affects more residential, commercial and industrial estab- 
lishments in West Medford and along Mystic Valley Parkway. This 
location was therefore considered unacceptable and was discarded 
in favor of those locations along the Mystic River Valley. 



ALTERNATIVE LOCATION F 

This location is common to the Alternate Location as far as 
Medford Street in Arlington. From Medford Street, this alternative 
extends through the Thompson Elementary School Playground, over 
Broadway, to the west of St. Paul's Cemetery, and along Alewife 
Brook Parkway to the Northwest Expressway in North Cambridge. 
This alternative was also considered unacceptable and therefore 
was discarded, because it has no advantage over those locations 
along the Mystic River Valley, and it causes excessive land dam- 
ages in East Arlington, affects the Thompson Elementary School, 
and isolates a section of East Arlington. 



ALTERNATIVE LOCATION G 

This location is common to the Recommended Location as far 
as Woburn Street in Lexington. From Woburn Street it extends 
over Maple Street, through the northern portion of the Great Mead- 
ows, over Lowell Street and then parallels Summer Street until it 
becomes common to Alternative Location C at the Summer Street 
Playground. As with Alternative Location C, previously discarded, 
this alternative also requires abandonment of the railroad. Because 
this location presents this disadvantage as well as the same addi- 
tional disadvantages as Alternative Location C, it was considered 
unacceptable and was discarded. 




INNER BELT AND EXPRESSWAY SYSTEM 



V-25 




V-26 



Exhibit B-4 
ROUTE 3 AND NORTHWEST EXPRESSWAY STUDY LINES — SHEET 1 



NNER BELT AND EXPRESSWAY SYSTEM 



^V v \lh%>.A-$ 




% 






\(\\Y PUBLIC RESERVATIONS, PARKS 



CEMETERIES, COUNTRY CLUBS 
RAILROADS & TRANSIT LINES 
CITY OR TOWN BOUNDARY LINES 



(£) JT) C||) STATE, U.S., INTERSTATE ROUTES 
URBAN RENEWAL AREAS 



GENERAL NEIGHBORHOOD RENEWAL 

PLAN 

PROJECT IN ADVANCE PLANNING 

PROJECT IN EXECUTION 

TERMINAL CONTROL POINT 
EXISTING EXPRESSWAYS 
OTHER PROPOSED EXPRESSWAYS 
RECOMMENDED LOCATION 
ALTERNATE LOCATION 

^J ALTERNATIVE LOCATIONS STUDIED 



SCALE 
CONTOUfi INTERVAL 20 FEET 

DATUM IS MEAN SEA LEVEL 



NNER BELT AND EXPRESSWAY SYSTEM 



Exhibit B-5 
ROUTE 3 AND NORTHWEST EXPRESSWAY STUDY LINES — SHEET 2 



V-27 



TABLE B-VIII 

ROUTE 3 EXPRESSWAY 

SUMMARY OF PHYSICAL EFFECTS 

NUMBER IN CATEGORY 





OR 


TOWN: 




Recom 


mended Location 














Alternate Location 










CITY 


Lexington 


Arlington 


Belmont 


Cambridge 




Woburn 


Lexington 


Winchester 


Arlington 


Medford 


Cambridge 


Somt 


srville 




CATEGORY 
















Totals 




















Totals 


Use of Structures 
Residential 
Retail 




51 


90 


49 




4 
6 


194 
6 


7 




25 


13 


126 


24 

1 


4 
4 




9 


208 
5 


Business 

Service 

Institutions 

Industry 

Recreation 






4 

1 


1 
1 


— 




3 


4 
1 
3 

2 


— 




— 


— 


2 
1 


2 


1 

1 




1 


3 
2 

1 

2 


Other Data 
Vacant Lots 
Households 
Employees 1 


Displaced 
displaced 


5 
52 
14 


5 
90 


1 
49 




6 
66 


15 

197 

80 


1 

7 




4 
25 


3 
13 


189 

8 


1 

33 

3 


8 

53 




20 
30 


9 

295 

94 


Tax Loss* 


rates. 




$46,960 


$47,490 


$38,940 


$35,400 


$168,790 


$5,440 


$25,230 


$20,360 


$70,250 


$15,820 


$26,200 


$25,320 


$188,620 


"Based on 1961 tax 





ANALYSIS OF RECOMMENDED AND 
ALTERNATE LOCATIONS 

TRAFFIC SERVICE 

The Recommended Location of the Route 3 Expressway, from 
Route 128 to the Northwest Expressway at Alewife Brook Parkway, 
provides traffic service for Burlington, Woburn, Lexington, Arling- 
ton, Belmont and Cambridge. From Route 128 to its junction with 
Route 2, approximately one-half of the assigned traffic originates 
in areas served by Route 3 outside of Route 128. Two local-serv- 
ice interchanges are provided between Route 128 and Route 2, one 
at Woburn Street and one at Massachusetts Avenue, both in Lex- 
ington. Each of these are diamond-type interchanges, providing 
complete traffic service. The local-service interchanges are de- 
signed to accommodate the assigned traffic and, where necessary, 
may be signalized. At the junction with Route 2, a Y-type direct- 
connector interchange is provided. Between this interchange and 



Alewife Brook Parkway, a total of eight parallel ramps, which act 
as split-diamond interchanges, are provided for local traffic serv- 
ice. These ramps serve traffic from the Arlington and Belmont 
Areas. At Alewife Brook Parkway, a full-service trumpet-type 
interchange is provided between the Parkway and Route 3. Local 
traffic service between the Route 3 frontage roads and Alewife 
Brook Parkway has also been provided. The frontage road system 
provided from Watertown Street, Lexington, to Alewife Brook Park- 
way will serve effectively to restore existing local service, as well 
as to augment the capacity of Route 3. 

In the Alternate Location, Route 3 provides traffic service for 
Burlington, Woburn, Winchester, Lexington, Arlington, Medford, 
and Somerville. Between Route 128 and Alewife Brook Parkway, 
local service is provided at Woburn Street, Lexington, at Ridge 
Street, Winchester, at Mystic Street, Arlington, and at High Street, 
Medford. With the exception of the interchange at Mystic Street, 
where a modified diamond interchange is provided because of 



topographic considerations, these are proposed as full diamond 
interchanges. 

The interchange of the Alternate Location of Route 3 with 
the connector between the Northwest and Northern Expressways 
is a fully-direct Y-type interchange. This connector extends from 
the Northwest Expressway, along Alewife Brook to its confluence 
with the Mystic River, and along the Mystic River to the Northern 
Expressway, which is now under construction. The interchange 
between this connector and Route 2 is also a fully-direct Y-type 
interchange. Local-service connections between Alewife Brook 
Parkway and the frontage roads on Route 2 are provided. Ale- 
wife Brook Parkway, from Route 2 northerly to the Route 3 inter- 
change, is designed to serve as a frontage road on each side of 
the proposed expressway. The existing Mystic Valley Parkway, 
from the Route 3 interchange easterly to the Northern Expressway, 
serves as a two-way frontage road. Local service is provided by 
four parallel ramps to the frontage roads. 



V-28 



INNER BELT AND EXPRESSWAY SYSTEM 



Totals 



$ 12,230 



TABLE B-IX 

ROUTE 3 EXPRESSWAY 

PROJECT COSTS 

In Thousands of Dollars 
RECOMMENDED LOCATION 



$4,680 



$2,930 



$1,185 



$2,116 



$ 23,141 



$ 406 



$ 23,547 



$ 3,533 



$ 6,034 










Construction Costs 






Demolition 
Cost 


Construction 

Cost Plus 

Demolition 


Engineering 

and 
Contingencies 

$ 830 
1,455 
1,248 


Right-of-Way 
Costs, 

Total Fair 
Market Value 




Section 
Number 


Structures 


Earthwork 


Pavement 


Utility 
Relocation 


Miscel- 
laneous 


Total 

Construction 

Cost 


Total 
Costs 


1 
2 
3 


$ 1,722 
4,093 
6,415 


$1,812 
1,714 
1,154 


$1,021 

1,590 

319 


$ 50 

1,055 

80 


$ 829 
977 
310 


$ 5,434 
9,429 
8,278 


$ / 94 

'272 

40 


$ 5,528 
9,701 
8,318 


$ 1,608 

3,634 

792 


$ 7,966 
14,790 
10,358 



$ 33,114 



ALTERNATE LOCATION 



4 
5 

Totals 



$ 3,240 
20,726 

$ 23,966 



$3,851 
2,367 

$6,218 



$1,585 
1,110 

$2,695 



$ 70 
840 

$ 910 



$1,277 
1,169 

$2,446 



$ 10,023 
26,212 

$ 36,235 



$ 129 

334 

$ 463 



$ 10,152 
26,546 

$ 36,698 



$ 1,522 
3,982 

$ 5,504 



$ 2,732 
3,345 

$ 6,077 



$ 14,406 
33,873 

$ 48,279 



COST SECTIONS 

1. Route 1 28 to Route 2 

2. Route 2 to Alewife Brook Parkway 

3. Alewife Brook Parkway to Northwest Expressway 

4. Route 1 28 to Alewife Brook Parkway 

5. Northwest-Northern Connector 



PROJECT COSTS PER MILE 



Recommended Alternate 



Number of Miles 


7.7 


9.2 


Construction and Engineering Cost/Mile 


$3,517 


$4,587 


Right-of-Way Cost/Mile 


$ 784 


$ 661 


Project Cost/Mile 


$4,301 


$5,248 



Traffic assigned to the interchange of the Northern Express- 
way with the Mystic Valley Parkway, presently under construction, 
indicates the desirability of a ramp from the southbound lane of 
the Northern Expressway to the westbound Mystic Valley Parkway. 
However, the ramps presently under construction at Salem Street 
and Main Street are of equal importance for the local traffic move- 
ments and preclude the provision of such a ramp. 

PHYSICAL AND FUNCTIONAL EFFECTS 

An evaluation of the physical effects of the Recommended 
and Alternate Locations of the Route 3 Expressway, shown in Table 
B-VIII, must take into consideration the proposed widening of exist- 



ing Route 2 currently being designed by the Department of Public 
Works. The majority of the effects upon the towns of Arlington 
and Belmont shown in Table B-VIII will occur as a result of this 
widening. Evaluating the data on this basis shows that approxi- 
mately 240 fewer households are affected by the Recommended 
Location than by the Alternate Location. Also, the annual tax 
loss to the communities, while only temporary, is at least $100,000 
less for the Recommended Location. Thus, by combining the two 
facilities, the resulting physical effect on the communities involved 
is far less. 

The Recommended Location, through Lexington to Route 2 
where the routes combine, passes for the most part through rela- 



tively sparsely developed areas, without any appreciable effect 
on existing municipal service districts. From Route 2 to Alewife 
Brook Parkway, the Expressway is located on the Arlington-Belmont 
Town Line, thereby having no effect on existing municipal service 
districts. 

The Alternate Location extends generally along the town 
lines of Woburn, Winchester, Lexington and Arlington, with mini- 
mum effect on the existing municipal service districts in these towns. 
However, a small section of Winchester is located between the 
Expressway and the Arlington and Lexington town lines, and a 
small section of Arlington is located between the Expressway and 
the Winchester and Medford town lines. These areas are, how- 



1NNER BELT AND EXPRESSWAY SYSTEM 



V-29 



ever, accessible to the main body of their respective towns via ma- 
jor surface streets which are bridged by the Expressway. In 
addition to causing greater physical effects when considered to- 
gether with the widening of Route 2, the Winchester Country Club, 
the Medford Boat Club and the shore properties along the Mystic 
Lakes are also seriously affected. 

The towns of Arlington, Belmont, Burlington, Lexington, Win- 
chester and Woburn, the major communities serviced by the Route 
3 Expressway, will experience a combined population growth of 
26,000 and an employment growth of 1 8,000, between the pres- 
ent and 1975. This population growth will stimulate the demand 
for new home construction in these communities, and will increase 
the real value of present residential and commercial properties. 
These new residential developments will, in turn, create a demand 
for new business and convenient shopping centers. Increased 
acccessibility afforded by the Expressway System, and a substan- 
tial labor force, will promote the development of additional 
commercial and industrial activities. Between now and 1975 
approximately 4,000 residential and 900 commercial and indus- 
trial acres will be developed in these communities in response to 
the increased accessibility provided by the Expressway System. 

As outlined in Industrial Land Needs Through I960, a recent 
publication of the Greater Boston Economic Study Committee, 
". . . Interstate (Route) 93 and Route 3 are likely to play a major 
role in the region's industrial future. They connect major popula- 
tion and labor concentrations with Route 128, and traverse popu- 
lous suburbs. . . ." The physical effects noted in Table B-VIII will 
create temporary short-run effects on the communities through 
which they pass, and the local governments will be affected by a 
temporary reduction in taxable properties. However, the communi- 
ties' tax bases will actually be strengthened as residential prop- 
erty values rise and new businesses and industries locate in these 
communities. 

COST ANALYSIS 

The summary of costs of the Recommended and Alternate 
Locations of the Route 3 Expressway is presented in Table B-IX. 
A comparison of the costs of constructing the expressways, as 



TABLE B-X 

ROUTE 3 EXPRESSWAY 

ROAD-USER BENEFIT ANALYSIS 



Item 


Recommended 
Location 


Alternate 
Location 


Length, miles * 


10.4 


12.7 


Annual Road-User Benefit 


$11,630,000 


$12,130,000 


Annual Cost of Expressway 


$ 2,798,000 


$ 3,680,000 


Road-User Benefit Ratio 


4.2 


3.3 



'Combined length Route 3, Route 2 and Northwest-Northern Connector 



shown on the Basic Design Exhibits, indicates an incremental saving 
of $15 million for the Recommended Location. However, two 
additional important considerations must be taken into account 
when evaluating the costs for the Route 3 Expressways. To allow 
greater dispersion of traffic for the Recommended Location, it is 
recommended that an expressway be extended along Alewife 
Brook and Mystic Valley Parkways similar to that shown for the 
Alternate Location. The cost of providing this facility is estimated 
to be $13.1 million. The Department of Public Works is currently 
planning to construct a limited-access facility along existing Route 
2. The cost attributable to this facility must be considered while 
evaluating the Alternate Location. The cost for the limited-access 
expressway along Route 2 is estimated to be $12.6 million for a 
six-lane roadway with frontage roads. When Routes 2 and 3 are 
combined, as recommended, an eight-lane roadway with frontage 
roads is required. 

A comparison of the cost estimates, in consideration of pro- 
viding an express facility along Route 2 for the Alternate Location, 
and an express facility along Alewife Brook Parkway for the Rec- 
ommended Location, is as follows: 



Recommended Location 
Northwest-Northern Connector 
Total 



$33.1 million 
13.1 million 



$46.2 million 



Alternate Location 
Route 2 Widening 
Total 



$48.3 million 
12.6 million 



$60.9 million 



Thus, by combining Routes 2 and 3, as recommended, more than 
$14.5 million will be saved. 

No particular foundation problems are anticipated for the 
construction of the Route 3 Expressway. The costs of the founda- 
tions for those structures generally located within the Boston Basin, 
where the Boston Blue Clay is prevalent, are based upon the use 
of pile construction. For those structures generally located outside 
the Basin, where the soil is characterized by frequent rock out- 
croppings and glacial till, the costs are based upon the use of 
spread footings. The construction of the expressway along Alewife 
Brook and the Mystic River Valley requires the relocation of ap- 
proximately 18,000 feet of Alewife Brook and the Mystic River. 
The Recommended Location requires 3,500 feet of viaduct con- 
struction while the Alternate Location requires 13,000 feet. The 
Alternate Location also requires the construction of an earth em- 
bankment 3,700 feet long through the Mystic Lakes, while the 
Recommended Location requires an earth embankment 1,700 feet 
long in Spy Pond. The costs outlined in Table B-IX are based upon 
these considerations. 

ROAD-USER BENEFIT ANALYSIS 

The results of the road-user benefit analyses for the Rec- 
ommended and Alternate Locations, shown in Table B-X, take into 
consideration the complete expressway system in the northwest 
sector: a Route 3 Expressway, a limited-access facility along Route 
2 and a connector between the Northwest and Northern Express- 
ways. The annual road-user benefit values more than justify the 
construction of either the Recommended or Alternate Locations as 
economically sound. The road-user benefit ratio, which compares 
travel on the new facility to existing street travel, results in a 4.2- 
to-one economic advantage by use of the Recommended Location 
as compared with the existing street network. The values also show 
an economic advantage for the Recommended Location over the 
Alternate Location. While the annual benefits for the Alternate 



V-30 



NNER BELT AND EXPRESSWAY SYSTEM 




are $500,000 greater, the annual costs are $880,000 greater, 
almost twice as much as the savings. 



SUMMARY 

The Route 3 Expressway, which has been completed as far 
north as Tyngsborough, near the New Hampshire State Line, pres- 
ently terminates at Route 128 in Burlington, and consequently does 
not provide traffic service between Route 128 and the Core Area. 
The residents of those communities outside of Route 128 must 
presently travel north or south on Route 1 28 to either Route 2 or 
Interstate Route 93, then easterly to the Core Area, or travel on 
highly congested local streets in Arlington, Lexington, Winchester 
and Woburn. The traffic generated within these communities must 
also travel on these limited-capacity surface streets. 



The Department of Public Works is currently planning to con- 
struct a limited-access highway from Route 128 to Alewife Brook 
Parkway, along the present location of Route 2. Integration of 
these plans with the Route 3 Expressway, as recommended herein, 
will provide efficient traffic service for the northwest sector in the 
most economical manner and with the least physical effect upon 
the communities involved. The completion of this facility, and its 
extension to the Inner Belt will relieve the existing local streets in 
this sector of heavy through-traffic, thus improving the environment 
of the residential and commercial areas. 

Construction of the Route 3 Expressway in the Recommended 
Location will: 

a. Provide better traffic service for the northwest sector at 
less total cost, including the improvement of Alewife 
Brook and Mystic Valley Parkways, than would the Alter- 
nate Location. 



c. 



Affect approximately 240 fewer households than the 

Alternate Location when all expressways in the northwest 

sector are considered. 

Result in a minimal effect on the communities through 

which it passes. 
With the completion of the Route 3 and Northwest Express- 
ways, the northwest sector will become readily accessible to all 
parts of the Metropolitan Area; its attractiveness as a residential 
area will continue and its desirability as an area for commercial 
and industrial expansion will be significantly enhanced, with the 
concomitant effect of an increase in real property value. The 
stimulated economy and increase in property values will broaden 
the communities' tax bases and result in the improved over-all 
economy of the region. 



L 5r :~^-w*r 




INNER BELT AND EXPRESSWAY SYSTEM 



V-31 



SECTION 4 -THE NORTHWEST EXPRESSWAY 



GENERAL 

The Northwest Expressway, which extends from Alewife 
Brook Parkway to the Inner Belt Expressway, is an integral section 
of Route 2. Route 2, which is one of the major east-west roadways 
included in the Federal-Aid Primary Highway System, extends to 
the New York State Line just west of North Adams, Massachusetts. 
At the present time the Commonwealth is planning to improve 
several sections of this roadway. The three-mile extension from 
Alewife Brook Parkway to the Inner Belt Expressway is included in 
this Study. When completed, Route 2 will be one of the major 
traffic distributors for this section of the Boston Metropolitan Area. 

The westerly control point for this Study, shown as Terminal 
Control Point 4 on Exhibit L-l, was established by previous engi- 
neering studies as the vicinity of the intersection of Alewife Brook 
Parkway and existing Route 2. This is one of the seven terminal 
control points previously described in Part II. The location of the 
easterly control point has been determined, as a result of this 
Study, to be the interchange with the Inner Belt Expressway, located 
between Lincoln Park, Somerville, and Donnelly Field, Cambridge. 
The area surrounding this interchange consists of many multi-family 
dwellings generally located within urban renewal areas. Location 
of the interchange within this area provides adequate spacing 
between the major interchanges, and permits the extension of 
direct-connector ramps from the Northwest Expressway to McGrath 
Highway. 

At the present time, there are no adequate surface streets 
or thoroughfares capable of accommodating the anticipated traf- 
fic within the corridor connecting the above control points. Traffic 
from the northwest quadrant having a destination in downtown 
Boston is presently forced to travel on existing Cambridge, Somer- 
ville and Boston surface streets which have the following serious 
limitations: 

a. Narrow, heavily-congested roadways with basically two 
travel lanes, such as Broadway, Elm Street, Somerville 
Avenue, Massachusetts Avenue, Rindge Avenue, Concord 
Avenue, Kirkland Street and Cambridge Street, which are 
located in high-density residential and commercial areas. 
Broadway and Massachusetts Avenue have capacity for 



four lanes of traffic for limited distances, 
b. Although major thoroughfares with four travel lanes, such 
as Alewife Brook Parkway, Fresh Pond Parkway, Memo- 
rial Drive, Soldiers Field Road, and Storrow Drive, par- 
tially serve the northwest areas, these roadways do not 
offer a continuous direct route to downtown Boston, have 
heavy local traffic, are used in part by traffic from the 
western corridor, and are also located essentially through 
areas of high-density residential and commercial devel- 
opment. 
The Fitchburg Division of the Boston and Maine Railroad 
extends in a direct line between the two control points. The area 
adjacent to the railroad forms a desirable corridor for this study. 
Expressway locations along this general corridor provide the 
shortest, most direct route to a connection with the Inner Belt 
Expressway. By maintaining a location parallel to the railroad, a 
future mass transit facility could be effectively incorporated in this 
corridor. Locations removed from the general corridor of the rail- 
road will have the adverse effects of passing through high-density 
residential developments, located both to the north and south of 
the railroad, and commercial activities located adjacent to Massa- 
chusetts Avenue, and also of isolating residential areas between 
the railroad and the Expressway. 

TOPOGRAPHY AND SUBSURFACE CONDITIONS 

At the easterly end of this location corridor, the Expressway 
is indicated above the typical Boston Basin deposits: an upper 
stratum of miscellaneous filled land and dense sand overlying 
upwards of 50 to 100 feet of blue clay, the crust of which is quite 
stiff before grading into the typical soft clay. Below the clay is 
encountered the glacial till, in turn underlain by the bedrock floor 
at depths varying to more than 150 feet. Near the mid-point of 
the route in the vicinity of Porter Square in Cambridge, the bed- 
rock floor shelves upward toward the north and west, and the 
thickness of the clay deposit decreases. The hills near Porter 
Square, of which Spring Hill is the most predominant, consist 
primarily of glacial till overlain by a thin mantle of miscellaneous 
fill and re-worked till. West and northwest of this area, the typical 
clay and till deposits laid upon the bedrock floor of the Boston 



Basin are again encountered between Porter Square and Alewife 
Brook Parkway. 

At Alewife Brook Parkway in the vicinity of Route 2, the depth 
to bedrock is quite erratic due to the presence of a buried pre- 
glacial valley system traversing the area, but is expected to be 
generally more than 100 feet. In some locations in this area, 
deposits of soft clay of considerable extent are indicated only a 
few feet below a surface stratum of sand and fill, while in other 
locations the surface deposits of granular materials above the clay 
are as much as 30 feet deep. The water table is generally 5 to 
10 feet below the surface throughout this corridor. 



LOCATIONS STUDIED 

Four locations for the Northwest Expressway were studied 
before a selection of the Recommended and Alternate Locations 
was made. These four basic locations are shown on Exhibit B-5 
and are referred to as follows: 

Recommended Location: Porter Square-South location. 
Alternate Location: Porter Square-North location. 
Alternative Location A: Railroad-North location. 
Alternative Location B: Railroad-South location. 

DESCRIPTION OF RECOMMENDED AND 
ALTERNATE LOCATIONS 

The Recommended Location extends southeasterly from the 
vicinity of Alewife Brook Parkway and existing Route 2, shown as 
Terminal Control Point 4, through the clay-pit area in North Cam- 
bridge, parallel to and south of the Fitchburg Division of the 
Boston and Maine Railroad, passes between Sears, Roebuck & 
Company and the railroad at Massachusetts Avenue, and con- 
tinues on the south side of the railroad to an interchange with the 
Recommended Location of the Inner Belt Expressway located be- 
tween Lincoln Park, Somerville, and Donnelly Field, Cambridge. 
At Porter Square the eastbound roadway is depressed and the 
westbound roadway is elevated over the eastbound roadway. 

The Alternate Location also begins in the vicinity of Alewife 
Brook Parkway and existing Route 2, and extends southeasterly 



V-32 



NNER BELT AND EXPRESSWAY SYSTEM 



through the clay pits. At Sherman Street, it crosses the Boston and 
Maine Railroad and continues parallel to the tracks on the north- 
ern side, crosses Massachusetts Avenue at Porter Square, recrosses 
the railroad at Beacon Street and continues on the south side of 
the railroad to an interchange with the Alternate Location of the 
Inner Belt Expressway north of Donnelly Field in Cambridge. 

Reference should be made to the Basic Design Exhibits for 
the Recommended and Alternate Locations. 

DESCRIPTION AND ANALYSIS OF 
OTHER LOCATIONS STUDIED 

In addition to the Recommended and Alternate Locations, 
Alternative Locations A and B were considered in detail and are 
described below. 

ALTERNATIVE LOCATION A 

This location begins in the vicinity of Alewife Brook Parkway 
and existing Route 2, as do all locations considered, and is com- 
mon to the Alternate Location as far <as Walden Street. From 
Walden Street this alternative crosses the Boston and Maine Rail- 
road, passes between the railroad and Sears, Roebuck & Company 
at Massachusetts Avenue, and rejoins the Alternate Location in the 
vicinity of Sacramento Street. This location offers no significant 
advantages over the Recommended or Alternate Locations, requires 
a 3,000-foot-long skewed-viaduct crossing of Walden Street, the 
Boston and Maine Railroad, Massachusetts Avenue and Beacon 
Street, and does not permit the dispersion of local-street inter- 
changes as effectively as the Alternate Location. This location 
was therefore considered to be unacceptable and was discarded. 

ALTERNATIVE LOCATION B 

This location is common to the Recommended Location as far 
as Walden Street. From Walden Street this alternative continues 
as a depressed section, occupying the railroad right-of-way, passes 
under Massachusetts Avenue and between Sears, Roebuck & 
Company and Somerville Avenue, and rejoins the Recommended 
Location at Sacramento Street. Since this location requires aban- 
donment of the railroad, which is not anticipated in the near future, 
it was considered unacceptable and therefore was discarded. 



TABLE B-XI 

NORTHWEST EXPRESSWAY 

SUMMARY OF PHYSICAL EFFECTS 

NUMBER IN CATEGORY 




Recommended Location 



Alternate Location 



CITY OR 


TOWN: 


Cambridge 


CATEGORY 






Use of Structures 






Residential 




106 


Retail 




10 


Wholesale 




2 


Business 




3 


Service 




6 


Institutions 




1 


Industry 




4 


Recreation 




— 


Other Data 






Vacant Lots 




1 


Households Displaced 


297 


Employees Displaced 


145 


Tax Loss* 




$128,160 


•Based on 1961 tax rates. 





Somerville 



258 
17 



557 
186 

$143,720 



ANALYSIS OF RECOMMENDED AND 
ALTERNATE LOCATIONS 

TRAFFIC SERVICE 

The Recommended Location provides complete local traffic 
service at two locations between Alewife Brook Parkway and the 
Inner Belt. A trumpet-type interchange is provided at Concord 
Avenue and Fresh Pond Parkway to provide traffic service for 
North Cambridge, East Belmont and East Watertown. Traffic as- 
signed to the Expressway System from Fresh Pond Parkway over- 
passes the existing rotary at Concord Avenue to eliminate weaving 
with the local traffic using the Parkway and Concord Avenue. A 
diamond-type interchange is provided near Massachusetts Avenue 
to serve the Porter Square area of Cambridge and West Somer- 
ville. Continuous frontage roads are provided from Sherman 
Street to Beacon Street. East of Massachusetts Avenue, Beacon 
Street and Hampshire Street serve as a two-way frontage-road 
system to integrate with the frontage-road system provided for 



Totals 



364 
27 
2 
4 
14 
1 
8 



1 
854 
331 



$271,880 



Cambridge 



95 
6 
1 

2 
1 
6 

1 



181 
143 

$79,950 



Somerville 



381 
16 

I 

7 
1 
6 

1 



888 
354 

$244,580 



Totals 



476 

22 

1 

1 

9 
2 

12 
2 



1,069 
497 

$324,530 



the Inner Belt. This frontage-road system will improve the traffic 
circulation throughout this corridor. 

The Alternate Location provides traffic service to the same 
geographical areas as the Recommended Location. The Fresh Pond 
Parkway-Concord Avenue interchange is identical to that shown 
for the Recommended Location. A diamond-type interchange is 
also provided near Massachusetts Avenue to serve the Porter 
Square area of Cambridge and West Somerville. Limited frontage 
roads are provided as necessary to maintain access to property 
which would otherwise be isolated, but the railroad crossings re- 
quired in this location preclude the provision of a continuous front- 
age road system. 

The number of ramps provided by either location is identical; 
however, the flexibility of ramp placement afforded by the Rec- 
ommended Location and the ability to provide a continuous front- 
age road system to augment the Expressway System and collect 
and distribute traffic, results in traffic service superior to that af- 
forded by the Alternate Location. 



INNER BELT AND EXPRESSWAY SYSTEM 




V-33 



Totals 



$ 23,837 



TABLE B-XII 

NORTHWEST EXPRESSWAY 

PROJECT COSTS 

In Thousands of Dollars 
RECOMMENDED LOCATION 









Construction Costs 






Demolition 
Cost 


Construction 

Cost Plus 

Demolition 


Engineering 

and 

Contingencies 


Right-of-Way 
Costs, 

Total Fair 
Market Value 




Section 
Number 


Structures 


Earthwork 


Pavement 


Utility 
Relocation 


Miscel- 
laneous 


Total 

Construction 

Cost 


Total 
Costs 


1 

2 


$ 9,020 
14,817 


$1,921 

522 


$ 523 
404 


$ 250 
293 


$ 846 
705 


$ 12,560 
16,741 


$ 266 

491 


$ 12,826 
17,232 


$ 1,924 
2,585 


$ 3,024 
2,862 


$ 17,774 
22,679 



$2,443 



$ 927 



$ 543 



$1,551 



$ 29,301 



$ 757 



$ 30,058 



$ 4,509 



$ 5,886 



$ 40,453 



ALTERNATE LOCATION 



1 
2 

Totals 



$ 11,022 
7,947 

$ 18,969 



$2,823 
1,071 

$3,894 



$ 426 
560 

$ 986 



$ 183 
360 

$ 543 



$ 529 
456 

$ 985 



$ 14,983 
10,394 

$ 25,377 



$ 240 
903 

$1,143 



$ 15,223 
11,297 

$ 26,520 



$ 2,284 
1,694 

$ 3,978 



$ 1,838 
4,706 

$ 6,544 



$ 19,345 
17,697 

$ 37,042 



COST SECTIONS — RECOMMENDED AND ALTERNATE LOCATIONS 

1. Alewife Brook Parkway to Massachusetts Avenue 

2. Massachusetts Avenue to Inner Belt Expressway 



PROJECT COSTS PER MILE 





Kecommendei 


a Alternate 


Number of Miles 


2.5 


2.8 


Construction and Engineering Cost/Mile 


$13,827 


$10,892 


Right-of-Way Cost/Mile 


$ 2,354 


$ 2,337 


Project Cost/Mile 


$16,181 


$13,229 



PHYSICAL AND FUNCTIONAL EFFECTS 

Both the Recommended and Alternate Locations generally 
parallel the Fitchburg Division of the Boston and Maine Railroad 
with minimum effect on the service districts and urban structure of 
Cambridge and Somerville. The interchanges with the Inner Belt Ex- 
pressway are generally located within proposed renewal areas in 
Cambridge and Somerville. The residences in these areas are 
essentially multi-family wood structures, many of which would be 
affected under urban renewal programs. The interchange with 
Fresh Pond Parkway and Concord Avenue is located within the 
clay-pit area in North Cambridge. These clay pits are the result 
of extensive brick manufacturing operations which have been dis- 
continued. At the present time there is sufficient open area in 



which to locate the Expressway, but recent commercial activities 
indicate that the area may be developed within the next few years. 
A comparison of the physical effects summarized in Table 
B-XI shows that fewer displacements result from the Recommended 
Location than from the Alternate Location. The differences are due 
primarily to the added length required to interchange the Alternate 
Location of the Northwest Expressway with the Alternate Location 
of the Inner Belt. The Recommended Location has decided advan- 
tages over the Alternate Location with respect to future develop- 
ment of the communities and integration with mass transit and the 
railroad. The Recommended Location is designed as a depressed 
roadway for a greater part of its length so that the sight of moving 
traffic is screened and the noise level is reduced. This design 



assumes retention of the railroad in its present location, but if 
operations are discontinued on the railroad, it is possible to main- 
tain a depressed roadway throughout the entire length. By main- 
taining a location parallel to one side of the railroad, a future mass 
transit facility could be effectively located in this corridor. In- 
creased accessibility afforded by the construction of the Recom- 
mended Location, provided with a continuous frontage-road system, 
together with sight-advertising advantages, will provide the stimulus 
for continued expansion of commercial and industrial activities 
within this corridor. The Alternate Location, which remains elevated 
throughout its entire length because of two railroad crossings, 
affects the Porter Square area and could limit the future expansion 
of this important shopping center. 



V-34 



INNER BELT AND EXPRESSWAY SYSTEM 



Major roadways and expressways in the Boston Metropolitan 
Area have played an important role in the past development of 
residential, commercial and industrial activities. In this area in par- 
ticular, the transportation and accessibility afforded by Alewife 
Brook Parkway, Route 2 and the Boston and Maine Railroad has 
stimulated commercial and industrial activities along Alewife Brook 
Parkway, Concord Avenue and Route 2 in North Cambridge. At 
the present time the existing street network is inadequate to handle 
the through-traffic in this area, thereby reducing the attractiveness 
of these facilities to the residents and shoppers who desire to use 
them. One of the most important functions of the Northwest Ex- 
pressway will be to relieve the local streets of this through traffic. 
With local street travel thus reduced, the environment of residen- 
tial and commercial areas will be greatly improved. This improved 
environment will, in turn, stimulate the development of new resi- 
dential and commercial activities. Without the Expressway System 
the existing residential and commercial establishments will continue 
to be penalized. The net effect of construction of the Northwest 
Expressway will be increased accessibility to all parts of the Bos- 
ton Metropolitan Area for these sections of Cambridge and Som- 
erville. Increased accessibility will in turn increase the real value 
of residential and commercial properties, thereby strengthening 
the tax bases of these communities. 

COST ANALYSIS 

The summary of costs of the Recommended and Alternate 
Locations is presented in Table B-XII. This table shows a relatively 
higher construction cost for the Recommended Location, attributable 
to constructing a depressed roadway below permanent ground- 
water elevation in the Porter Square area and in the vicinity of 
Park and Washington Streets, requiring reinforced concrete walls 
and base, and membrane waterproofing. 

No unusual foundation conditions are anticipated in con- 
struction of the Northwest Expressway. Along this corridor consid- 
erable unsuitable material is present. In some areas this material 
will have to be removed or the surface preloaded to consolidate 
the underlying deposits. The costs of the foundations for those 
structures located within the Boston Basin, where blue clay is preva- 
lent, are based upon the use of pile construction. For those struc- 



TABLE B-XIII 

NORTHWEST EXPRESSWAY 

ROAD-USER BENEFIT ANALYSIS 





Recommended 


Alternate 


item 


Location 


Location 


Length, miles 


2.5 


2.8 


Annua! Road-User Benefit 


$12,403,000 


$9,535,000 


Annual Cost of Expressway 


$ 2,347,000 


$2,164,000 


Road-User Benefit Ratio 


5.3 


4.4 



tures generally within the Porter Square area, where foundation 
conditions are good, the costs are based upon the use of spread 
footings. The design of the Recommended Location requires 2,650 
feet of viaduct as compared to 3,550 feet for the Alternate Loca- 
tion. The Recommended Location also requires the use of approxi- 
mately 1 ,800 feet of a depressed waterproofed section for the 
eastbound roadway in the Porter Square area, and 2,200 feet of 
this type of construction in the vicinity of Park and Washington 
Streets. The Alternate Location is an elevated roadway on either 
fill or viaduct throughout its entire length. 

ROAD-USER BENEFIT ANALYSIS 

The annual road-user benefit values, shown in Table B-XIII, 
more than justify the construction of either location as economically 
sound, and show an advantage in favor of the Recommended Lo- 
cation. The road-user benefit ratio, which compares travel on the 
new facility to existing street travel, results in a 5.3-to-one economic 
advantage by the use of the Recommended Location. Comparison 
of the annual road-user benefit values for the two locations shows 
incremental savings of more than $2.8 million per year for the 
road users in favor of the Recommended Location, which reflects 
the higher traffic volumes assigned thereto. 



SUMMARY 

Route 2, currently being designed as a limited-access ex- 
pressway from Route 128 to Alewife Brook Parkway, when com- 



pleted will, along with the Route 3 Expressway, be the major 
traffic distributor for the northwest sector of the Boston Metropolitan 
Area. To complete the system of circumferential and radial ex- 
pressways for this area, Route 2 must be extended on new location 
from Alewife Brook Parkway through Cambridge and Somerville 
to the Inner Belt Expressway. At the present time there are no 
roadways along this corridor that are capable of accommodating 
the anticipated traffic. 

Traffic from the northwest sector must presently travel on 
limited-capacity streets located in high-density residential and com- 
mercial areas of Cambridge and Somerville. The attractiveness of 
the commercial and residential areas is diminished, because of the 
heavy volumes of through-traffic that now must travel on the local 
streets. These streets must be relieved of the burden of through- 
traffic to stimulate commercial activity and to improve the environ- 
ment of the area for residential use. 

Construction of the Northwest Expressway in the Recom- 
mended Location will: 

a. Provide efficient traffic service and maximum flexibility 
for traffic distribution in this corridor, due to the ramp loca- 
tions and by the provision of a continuous frontage-road 
system to augment the Expressway. 

b. Cause less displacement of families and employees, cause 
fewer residential structures to be demolished, result in a 
smaller cost of right-of-way acquistion, and a smaller 
total tax loss to Cambridge and Somerville than would 
the Alternate Location. 

c. Result in approximately $12.4 million in direct annual 
savings to the road users by use of the Expressway in lieu 
of use of the existing street network, or $2.8 million 
more than the annual savings provided by the Alternate 
Location. 

Construction of the Northwest Expressway and its integration 
with the Expressway System presents an opportunity for Cambridge 
and Somerville to undertake a program of urban renewal, with 
concurrent residential, commercial and industrial developments 
which will greatly strengthen the communities' economic positions 
by more productive and efficient land use. 




INNER BELT AND EXPRESSWAY SYSTEM 



V-35 



SECTION 5 -THE NORTHERN EXPRESSWAY, 



GENERAL 

Interstate Route 93, when completed, will serve northern New 
England from Boston, Massachusetts, to St. Johnsbury, Vermont, 
via central New Hampshire. The Northern Expressway will be 
part of this route. The northerly control point for this Study, shown 
as Terminal Control Point 6 on Exhibit L-l, has been established 
as the end of the present construction of Interstate Route 93 in 
Medford. This is one of the seven terminal control points previously 
outlined in Part II. The location of the southerly control point was 
established, as a result of this Study, to be the interchange of the 
Northern Expressway with the Inner Belt Expressway. The Rec- 
ommended Location of the interchange is centered in an industrial 
and commercial complex located between Washington Street and 
the Boston and Maine Railroad yards, at the Somerville-Boston 
City Line. Many of the structures located in this area are in poor 
condition. The Alternate Location of the interchange is in a resi- 
dential area for which urban renewal is planned, between Broad- 
way and Washington Street near the Somerville-Boston City Line. 

At the present time there are no adequate major thorough- 
fares capable of accommodating the anticipated traffic within the 
corridor connecting these control points. All traffic is now forced 
to use sections of the Mystic Valley Parkway, Mystic Avenue, 
Broadway, McGrath Highway and Rutherford Avenue. In many 
places, only one lane is available for moving traffic in each direc- 
tion, thereby causing serious congestion and delay. 

The corridor of study contains numerous existing or proposed 
developments which have a particularly important bearing on the 
location of the Expressway. These developments are the Mystic 
River Basin as proposed by the Metropolitan District Commission, 
public housing, St. Polycarp's and St. Benedict's Churches, Foss 
Park, First National Stores storage warehouses, and the Boston 
and Maine Railroad. 

TOPOGRAPHY AND SUBSURFACE CONDITIONS 

The northerly half of the expressway is located within the flood 
plain deposits of the Mystic River Basin. Previous boring data 
indicates 10 to 20 feet of very soft peat and organic river silts 



overlying the typical blue clay deposits of varying depth. Glacial 
till of varying thickness is generally encountered beneath the clay. 
Depth to bedrock is erratic due to the presence of pre-glacial 
rock valleys and gorges which traverse the area, but maximum 
depths of about 150 feet should be anticipated with an average 
of approximately 60 feet. Much of this area has miscellaneous fill 
of recent origin overlying these native deposits. 

For the southerly portion of the expressway extending from 
the edge of the Mystic River Basin to the Inner Belt interchange 
area, sub-surface investigations generally indicate surface deposits 
of 30 to 50 feet of fluvio-glacial sand and glacial till overlying 
relatively shallow bedrock. Localized deposits of clay have been 
encountered in this portion, particularly near Foss Park west of 
Mystic Avenue and also at the Boston and Maine Railroad yards 
off Washington Street. The latter deposit appears to follow a 
remnant of the pre-glacial valley system beneath the interchange 
area. 



LOCATIONS STUDIED 

The limited length of the Expressway, land-use restrictions, 
and traffic service requirements restrict the number of possible 
locations of this Expressway. In the Ten Hills Area, the only loca- 
tions for the Expressway are on either side of Ten Hills, one be- 
tween Bailey Road and Mystic Avenue, the other between Shore 
Drive and Wellington Bridge. Southeasterly of Ten Hills, three loca- 
tions are possible: one parallel to Mystic Avenue, one parallel to 
Middlesex Avenue, and one along the Boston and Maine Railroad. 
The three basic locations are shown on Exhibit B-6 and are referred 
to as follows: 

Recommended Location: Mystic Avenue location. 
Alternate Location: Middlesex Avenue location. 
Alternative Location A: Boston and Maine Railroad location. 

DESCRIPTION OF RECOMMENDED AND 
ALTERNATE LOCATIONS 

The Recommended Location extends southeasterly from the 



end of the present construction of Interstate Route 93 in the vicinity 
of the Mystic Valley Parkway in Medford, across the marshes of 
the Mystic River Reservation. It parallels Mystic Avenue, and after 
entering Somerville continues southeasterly between Bailey Road 
and Mystic Avenue to the Fellsway (U.S. Route 1). From the Fells- 
way the location extends southeasterly, across Mystic Avenue and 
Broadway, to a directional interchange with the Recommended 
Location of the Inner Belt. 

The Alternate Location begins at the same point as the Rec- 
ommended Location and proceeds easterly across the Mystic River 
Reservation, continues southerly over Shore Drive and the Fellsway, 
proceeds parallel to and just west of Middlesex Avenue, crosses 
Mystic Avenue and Broadway, and extends to a directional inter- 
change with the Alternate Location of the Inner Belt. 

Reference should be made to the Basic Design Exhibits for 
the Recommended and Alternate Locations. 



DESCRIPTION AND ANALYSIS OF 
OTHER LOCATIONS STUDIED 

ALTERNATIVE LOCATION A 

This location is common to the Alternate Location as far as 
the vicinity of the Fellsway and Shore Drive. After crossing the 
Fellsway it extends easterly along the banks of the Mystic River, 
and continues southerly, as a viaduct structure, over the tracks of 
the Portland Division of the Boston and Maine Railroad. It paral- 
lels the railroad, overpassing the Mystic Avenue and Broadway 
bridges, and interchanges with the Inner Belt in the Boston and 
Maine Railroad yards. 

In this location, the lack of local surface streets and the prox- 
imity of large commercial and industrial developments adjacent 
to the railroad and the Mystic River preclude the provision of ade- 
quate local traffic service. This alternative also limits the use of 
the Mystic River Basin for recreational purposes, and requires an 
extensive viaduct section in order to maintain operations on the 
Boston and Maine Railroad. For these reasons, this location was 
considered unacceptable and was therefore discarded. 



V-36 



INNER BELT AND EXPRESSWAY SYSTEM 








CONTOUR INTERVAL 20 FEET 

DATUM IS MEAN SEA LEVEL 



Exhibit B-6 
NORTHERN EXPRESSWAY STUDY LINES 



INNER BELT AND EXPRESSWAY SYSTEM 



V-37 



ANALYSIS OF RECOMMENDED AND 
ALTERNATE LOCATIONS 

TRAFFIC SERVICE 

The Recommended Location of the Northern Expressway ex- 
tends from the Interstate Route 93 interchange now under con- 
struction in Medford, to an interchange with the Inner Belt south 
of Broadway, Somerville. A complete local-service interchange 
serving Somerville and Medford is provided in the vicinity of Foss 
Park. Traffic service is provided between the Northern Expressway 
and the Sullivan Square overpass, to permit direct access to 
Charlestown and the North Terminal area via Rutherford Avenue 
and its extension to City Square, Charlestown, without requiring 
travel on the Inner Belt. Revisions to the local street pattern as 
shown on the Basic Design Exhibits, together with a coordinated 
signal system, are recommended to accommodate the assigned 
ramp traffic, and to facilitate distribution of this traffic to the exist- 
ing arterial streets. Frontage roads are provided to maintain con- 
tinuity of the local street system. The Recommended Location 
local-service interchange at the Fellsway is a split-diamond type, 
with the expressway ramps terminating at frontage roads on either 
side of the Fellsway, thereby providing for maximum flexibility of 
traffic distribution to the local street network in this area. 

The Alternate Location provides traffic service to the same 
geographical areas as the Recommended Location. However, the 
local service interchange in the triangular area bounded by the 
Fellsway, Mystic Avenue, and Middlesex Avenue does not permit 
the distribution of assigned ramp traffic to the major arterial streets 
as well as does the interchange for the Recommended Location. 
Traffic service to the Sullivan Square area is identical with that of 
the Recommended Location, with frontage roads provided to main- 
tain continuity of the local street system. 

PHYSICAL AND FUNCTIONAL EFFECTS 

The Recommended Location extends closer to Boston than the 
Alternate Location, thereby increasing the physical effects of the 
Recommended Location over those of the Alternate Location. How- 
ever, the physical and functional effects associated with the Inner 

V-38 



TABLE B-XIV 

NORTHERN EXPRESSWAY 

SUMMARY OF PHYSICAL EFFECTS 

NUMBER IN CATEGORY 



Recommended Location 



Alternate Location 



CITY OR TOWN: 


Somerville 


CATEGORY 




Use of Structures 




Residential 


193 


Retail 


26 


Wholesale 


2 


Business 


1 


Service 


17 


Institutions 


1 


Industry 


5 


Recreation 




Other Data 




Vacant Lots 


— 


Households Displaced 


503 


Employees Displaced 


250 


Tax Loss* 


$213,390 


'Based on 1961 tax rates. 





Medford 



$3,020 



Belt favor the Recommended Location of the interchange with the 
Northern Expressway over the Alternate Location, and therefore 
must be considered in the over-all analysis of the most advantage- 
ous location of this section of the Expressway System. The Rec- 
ommended Location causes a minimal effect on future use of the 
Mystic River Basin. The Alternate Location passes through the 
middle of this basin and has a detrimental effect on this proposed 
development. While the use of viaduct would not deplete the 
storage volume of the basin for flood control purposes, it would 
seriously impair the use of the basin for recreational purposes. 

The Inner Belt interchange for the Recommended Location is 
primarily located in the railroad yards and in the industrial and 
commercial area adjacent to the yards. This location has the least 
effect on nearby residential areas. The Inner Belt interchange for 
the Alternate Location affects the residential area between Broad- 
way and Washington Street, but has less effect on business and 
industry. 

The physical effects of construction of either location in Med- 





Somerville 


lis 




193 


147 


26 


9 


2 


— 


1 


— 


17 

1 
5 


3 


7 


1 


— 


1 
503 


396 


250 


229 



Medford 



Totals 



147 
9 



1 
396 
229 



$216,410 



$141,860 



$3,020 



$144,880 



ford, as shown in Table B-XIV, do not impair the physical structure 
of that city, since these locations are along the Mystic River Valley. 

Non-users of the Expressway will derive both tangible and 
intangible benefits. A properly designed, landscaped, and main- 
tained expressway system tends to increase the value of real estate 
in its corridor of influence. With adequate access and egress 
ramps, new business will be generated by the road users. Long- 
time gains will be realized by the cities of Medford and Somerville 
by virtue of the stimulated economies of neighborhood businesses 
and the certainty of renewed interest and activity in areas of com- 
mercial and industrial development. 

The City of Somerville is currently planning to correlate urban 
renewal and commercial and industrial developments with the Ex- 
pressway. This includes a major renewal project bounded by 
McGrath Highway, Broadway, and the Northern Expressway. A 
commercial development is planned for the area bounded by 
McGrath Highway, Broadway, Cross Street East, and the Northern 
Expressway at Mystic Avenue. Industrial development is proposed 

/ 
INNER BELT AND EXPRESSWAY SYSTEM 



Totals 



$ 7,031 



TABLE B-XV 

NORTHERN EXPRESSWAY 

PROJECT COSTS 

In Thousands of Dollars 
RECOMMENDED LOCATION 



$2,924 



$ 733 



$ 195 



$ 629 



$ 11,512 



$ 388 



$ 11,900 



$ 1,786 



$ 4,042 










Constructio 


n Costs 






Demolition 
Cost 


Construction 

Cost Plus 

Demolition 


Engineering 

and 

Contingencies 

$ 590 
990 
206 


Right-of-Way 
Costs, 

Total Fair 
Market Value 




Section 
Number 


Structures 


Earthwork 


Pavement 


Utility 
Relocation 


Miscel- 
laneous 


Total 

Construction 

Cost 


Total 
Costs 


1 
2 
3 


$ 585 
5,331 
1,115 


$2,322 

541 

61 


$ 479 

205 

49 


$ 90 
70 
35 


$ 365 

211 

53 


$ 3,841 
6,358 
1,313 


$ 89 

241 

58 


$ 3,930 
6,599 
1,371 


$ 636 

2,773 

633 


$ 5,156 

10,362 

2,210 



$ 17,728 



Totals 



$ 7,111 



ALTERNATE LOCATION 



1 


$ 2,790 


$4,592 


$ 425 


$ 35 


$ 247 


$ 8,089 


$ 13 


$ 8,102 


$ 1,215 


$ 375 


$ 9,692 


2 


2,172 


248 


158 


62 


125 


2,765 


46 


2,811 


422 


585 


3,818 


3 


2,149 


218 


168 


68 


155 


2,758 


239 


2,997 


450 


1,756 


5,203 



$5,058 



$ 751 



$ 165 



$ 527 



$ 13,612 



$ 298 



$ 13,910 



$ 2,087 



$ 2,716 



$ 18,713 



COST SECTIONS — Recommended Location 



1. Mystic Valley Parkway to the Fellsway 

2. Fellsway to Broadway 

3. Broadway to Perkins Street 

Alternate Location 



1. Mystic Valley Parkway to the Fellsway 

2. Fellsway to Mystic Avenue 

3. Mystic Avenue to Broadway 



PROJECT COSTS PER MILE 





Recommend* 


;d 


Alternate 


Number of Miles 


1.8 




1.7 


Construction and Engineering Cost/Mile 


$7,603 




$ 9,410 


Right-of-Way Cost/Mile 


$2,246 




$ 1,598 


Project Cost/Mile 


$9,849 




$11,008 



for areas located to the east of the Expressway, adjacent to the 
Somerville-Boston City Line. The net effect of the Expressway will 
be to increase the tax base of Somerville, so that the temporary 
loss resulting from the displacement of properties will be more 
than regained. 

COST ANALYSIS 

The summary of costs of the Recommended and Alternate 
Locations is presented in Table B-XV. This table shows a higher 



construction cost for the Alternate Location, primarily attributable 
to the required excavation of considerable unsuitable material in 
the Mystic River Basin and its replacement with granular material. 
No unusual foundation conditions are anticipated for the construc- 
tion of this Expressway. The costs of the foundations for those 
structures located to the north and west of Ten Hills, where blue 
clay is prevalent, are based upon the use of pile construction. For 
those structures located within the Ten Hills area and from the 
Ten Hills area to the Inner Belt, where foundation conditions are 



good, the costs are based upon the use of spread footings. The 
design of the Recommended Location requires 1,700 feet of via- 
duct as compared to 1,500 feet for the Alternate Location. The 
Recommended Location also requires the rechanneling of 1,800 
feet of the Mystic River, while 2,500 feet of rechanneling are re- 
quired for the Alternate Location. 

ROAD-USER BENEFIT ANALYSIS 

The results of the road-user benefit analyses as applied to 



INNER BELT AND EXPRESSWAY SYSTEM 



V-39 



the Recommended and Alternate Locations of the Northern Ex- 
pressway are shown in Table B-XVI. The road-user benefit analyses 
more than justify the construction of either the Recommended or 
Alternate Location as economically sound. The road-user benefit 
ratio shows about a 3.9-to-one economic advantage by use of 
the Recommended Location rather than the existing surface street 
network. The road-user benefit ratio for the Alternate Location 
shows a 3.3-to-one economic advantage. Comparison of the an- 
nual road-user benefits and the annual costs shows an economic 
advantage in favor of the Recommended Location by virtue of 
greater annual benefits with less annual costs. 



SUMMARY 

Interstate Route 93, which extends from Boston through New 
Hampshire to St. Johnsbury, Vermont, has been constructed from 
the New Hampshire State Line to Medford Square; a one-mile 
section from Medford Square to the Mystic Valley Parkway, near 
the Somerville City Line, is presently under construction. The com- 
pletion of the Northern Expressway to the Mystic Valley Parkway 
will induce heavy volumes of through-traffic to travel on existing 
streets in Somerville, which are limited in capacity and not ade- 
quate to handle the anticipated traffic. 



TABLE B-XVI 

NORTHERN EXPRESSWAY 

ROAD-USER BENEFIT ANALYSIS 



Item 



Length, miles 



Annual Road-User Benefit 



Annual Cost of Expressway 



Road-User Benefit Ratio 



Recommended 


Alternate 


Location 


Location 


1.8 


1.7 


$4,029,000 


$3,677,000 


$1,034,000 


$1,102,000 


3.9 


3.3 



Interstate Route 93 must be extended southeasterly to the 
Inner Belt to complete this radial expressway. Completion of the 
Northern Expressway will relieve the existing streets of their burden 
of through-traffic, thereby improving the environment of commercial 
and residential activities. With the attractiveness of the area im- 
proved by removal of through-traffic, there will be a concomitant 
increase in the real value of commercial and residential property 
and a necessary stimulus for commercial and industrial develop- 
ment. 



Construction of the Northern Expressway in the Recommended 
Location will: 

a. Provide maximum flexibility of traffic distribution to the 
local street network. 

b. Provide more efficient traffic service for $1 million less 
total cost than the Alternate Location. 

c. Result in approximately $4 million in direct annual savings 
to the road users by use of the Expressway in lieu of the 
existing street network. 

d. Permit development of an attractive fresh-water basin in 
the Mystic River estuary for flood control purposes and 
recreational activities, whereas the Alternate Location 
would not permit the development of the basin for recrea- 
tional activities. 

Construction of the Northern Expressway and its integration 
with the Expressway System presents an opportunity for Somer- 
ville to advance its urban renewal program and to realize effec- 
tively its over-all community objective of commercial and industrial 
expansion. The successful completion of the Expressway System 
will increase the value of Somerville's existing commercial and in- 
dustrial facilities and encourage the development of new activities. 
The development of new industry and the expansion of existing in- 
dustry will improve the present imbalance of the economy in Somer- 
ville. 










^^E3=F i -3=3=J 






4. 

s 



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T.fc-K.. 



V-40 



INNER BELT AND EXPRESSWAY SYSTEM 





EXHIBIT B-7 

KEY MAP 

RECOMMENDED LOCATION 



INNER BELT AND EXPRESSWAY SYSTEM 



V-41 



EXHIBIT B-8 



SOUTHWEST EXPRESSWAY 
SEE EXHIBIT NO. B -15 



^ • 




4 



197 5 TRAFFIC ASSIGNMENT 



CONSTRUCTION 
COMPLETED 

TERMINAL 
CONTROL 
POINT NO.I 




INNER BELT 

RECOMMENDED LOCATION 



HORIZONTAL SCALE 400 



VERTICAL SCALE 40 



MASSACHUSETTS AVENUE TO BROOKLINE AVENl 

BOSTON 



SCALE IN FEET 



V-42 



INNER BELT AND EXPRESSWAY 



EXHIBIT B-9 




M.T.A. TUNNEL EXTENOEO 



BROOKLINE AVENUE TO MEMORIAL DRIVE 

BOSTON-BROOKLINE-CAMBRIDGE 



HORIZONTAL SCALE 400 



400 



VERTICAL SCALE 40 



SCALE IN FEET 





INNER BELT 

RECOMMENDED LOCATION 



NNER BELT AND EXPRESSWAY SYSTEM 



V-43 



EXHIBIT B-10 






NORTHWEST EXPRESSWAY 
SEE EXHIBIT NO. B-24 




.&£ ~m 



INNER BELT 

RECOMMENDED LOCATION 



HORIZONTAL SCALE 400 



VEHTICAL SCALE 40 



40 80 

SCALE IN FEET 



MEMORIAL DRIVE TO McGRATH HIGHWAY 
CAMBRIDGE-SOMERVILLE 



V-44 



INNER BELT AND EXPRESSWAY SYSTEI 



EXHIBIT B-ll 



TO NORTHEAST EXPRESSWAY 




1975 TRAFFIC ASSIGNMENT 



DESIGN COMPLETED 




CON* 



20 






V 


A D U C T 


< 2 LEVEL) 














20 




^ 






BOSTON 


a MAINE 


RAILROAD 


YAR03 






EXISTING 


GROUND 




BASE 
















- 








BASE 



McGRATH HIGHWAY TO PRISON POINT BRIDGE 
SOMERVILLE-BOSTON 



HORIZONTAL SCALE 400 



400 



/ERTICAL SCALE 40 



40 

SCALE IN FEET 



'NNER BELT AND EXPRESSWAY SYSTEM 






INNER BELT 

RECOMMENDED LOCATION 



J 



V-45 



EXHIBIT B-12 




V-46 



INNER BELT AND EXPRESSWAY SYStf 



EXHIBIT B-13 




■ME o 



BASE .fl- 



NEPONSET VALLEY PARKWAY TO METROPOLITAN AVENUE 

BOSTON 



I0RIZ0NTAL SCALE 400 



VERTICAL SCALE 40 



SCALE IN FEET 



INNER BELT AND EXPRESSWAY SYSTEM 



SOUTHWEST EXPRESSWAY 

RECOMMENDED LOCATION 

V-47 



EXHIBIT B-14 



1 




1975 TRAFFIC ASSIGNMENT 



s 



100 




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SOUTHWEST EXPRESSWAY 

RECOMMENDED LOCATION 



HORIZONTAL SCALE 400 



VERTICAL SCALE 40 



40 

SCALE IN FEET 



METROPOLITAN AVENUE TO THE ARBORWAfl 

BOSTON 



V-48 



INNER BELT AND EXPRESSWAY SYS 



EXHIBIT B-15 




LIMIT OF COST ESTIMATE 



SOUTHWEST EXPRESSWAY 



LIMIT OF COST ESTIMATE 



INNER BELT 




© 



W>© 











^^^^^ 17Bfl 


350 __^^^^^^^^ 




3320 ^^^^^^^^^ 


TRAFFIC 


ASSIGNMENT 


U 

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1975 





66000 
5810 



66000 

5810 




THE ARBORWAY TO VERNON STREET 
BOSTON 



HORIZONTAL SCALE 400 
VERTICAL SCALE 40 



100 

z 

40 

SCALE IN FEET 



SOUTHWEST EXPRESSWAY 

RECOMMENDED LOCATION 



INNER BELT AND EXPRESSWAY SYSTEM 



V-49 



EXHIBIT B-16 



111 

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40 






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' BOSTON MAIN DRAINAGE 
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BASE -40 






BASE -40 








CONNECTOR A 



















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CONNECTOR 



SOUTHWEST EXPRESSWAY AND INNER BELT 

RECOMMENDED LOCATION 



HORIZONTAL SCALE ZOO 



SO, 



VERTICAL SCALE 20 



20 

SCALE IN FEET 





40 


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S'W.CXPIESSWA. 

N0RTHB{UND_Q.5 o / 




100 



CONN ECTOR D 



INTERCHANGE PROFILES 
BOSTON 



v-so 



INNER BELT AND EXPRESSWAY SYST 



EXHIBIT B-17 




INNER BELT AND EXPRESSWAY SYSTEM 



V-51 



EXHIBIT B-18 



a. 

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20 


*•* rim...... ^0* 000 "^ 
















/ 20 




£ HSTING C-flOUNO 








NEW YORK CENTRAL R.R. 


TRACKS 


— _ 









AELOCATEO NEW YORK CENTRAL 



CONNECTOR A 





CONNECTOR B 



CONNECTOR C 
CONNECTOR D 



INNER BELT AND MASSACHUSETTS TURNPIKE 

RECOMMENDED LOCATION 



HORIZONTAL SCALE 200 



200 



400 

3 



VERTICAL SCALE 20 



O 20 

SCALE IN FEET 



INTERCHANGE PROFILES 
BOSTON-BROOKLINE-CAMBRIDGE 



V-52 



INNER BELT AND EXPRESSWAY SYS 



>GE I 
;teJ 



EXHIBIT B-19 




SEE EXHIBIT NO. B-IO 



INTERCHANGE PLAN 
BOSTON-BROOKLINE-CAMBRIDGE 



ZOO 400 



SCALE IN FEET 



INNER BELT AND MASSACHUSETTS TURNPIKE 

RECOMMENDED LOCATION 



j 



lN NER BELT AND EXPRESSWAY SYSTEM 



V-53 



EXHIBIT B-20 



W B U R N 




16900 
2230 



GRADING AND 
DRAINAGE COMPLETED 












a 
a 

3 
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220 1 








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8ASE_I«2. 



ROUTE 3 EXPRESSWAY 

RECOMMENDED LOCATION 



HORIZONTAL SCALE 400 



VERTICAL SCALE 40 



40 

SCALE IN FEET 



BOO 

a 

80 



ROUTE 128 TO WOBURN STREET 
BURLINGTON-LEXINGTON 



V-54 



NNER BELT AND EXPRESSWAY SYSTl 



EXHIBIT B-21 




B*SE i&u 



WOBURN STREET TO APPLETON STREET 
LEXINGTON-ARLINGTON 



VERTICAL SCALE 40 



40 

SCALE IN FEET 



ROUTE 3 EXPRESSWAY 

RECOMMENDED LOCATION 



INNER BELT AND EXPRESSWAY SYSTEM 



V-55 



EXHIBIT B-22 







57000 
59 



£?© 



57000 
58 



1-°© 




54960 
5550 







54960 

5550 



© 



2220 
250 



53740 
5270 



© 



£ 2220 
5 ~2*0- 



© 




1975 TRAFFIC ASSIGNMENT 



© 



w © 











a. 


m 








320 


y \^^ 






320 


300 


t ^>- — ^\^ 






2 BO 






S^^^ / ^"^^^CT 




. 280 


260 


<€?** 








260 




j£g>^ 






240 




+ rjrt^ ^^^^^— — 


^^****' 




^v^°^% \ 


\ 


220 


220 




ZOO 












2.00 


uueiao 












^te^£ 180 





















ROUTE 3 EXPRESSWAY 

RECOMMENDED LOCATION 



HORIZONTAL SCALE 400 



VERTICAL SCALE 40 



40 

SCALE IN FEET 




APPLETON STREET TO LAKE STREET 
ARLINGTON-BELMONT 



V-56 



INNER BELT AND EXPRESSWAY SYSTEM 



EXHIBIT B-23 



SEE EXHIBIT NO. 8-24 




LAKE STREET TO SHERMAN STREET 
BELMONT-ARLINGTON-CAMBRIDGE 



HORIZONTAL SCALE 400 



VERTICAL SCALE 40 



40 

SCALE IN FEET 



ROUTE 3 EXPRESSWAY - NORTHWEST EXPRESSWAY 

RECOMMENDED LOCATION 



.NN 



ER BELT AND EXPRESSWAY SYSTEM 



V-57 



EXHIBIT B-24 




SHERMAN STREET TO CONCORD AVENUE 

CAMBRIDGE-SOMERVILLE 



HORIZONTAL SCALE 400 
VERTICAL SCALE 40 



400 

2 

40 

SCALE IN FEET 



NORTHWEST EXPRESSWAY 

RECOMMENDED LOCATION 



INNER BELT AND EXPRESSWAY SYSTE 



M 



V-59 



EXHIBIT B-25 



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BOSTO 








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60 


60 




























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20 






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20 








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CONNECTOR A 



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60 




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20 












20 












FXISTINQ ( 




GROUND 


BASE 














BASE 



CONNECTOR C 



NORTHWEST EXPRESSWAY AND INNER BELT 

RECOMMENDED LOCATION 



(OniZONTAL SCALE 200 



CONNECTOR B 





GO 




U 




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60 


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VIADUCT 






20 




/ 












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BASE 



200 



400 

3 



VERTICAL SCALE 20 



O 20 

SCALE IN FEET 



INTERCHANGE PROFILES 
CAMBRIDGE-SOMERVILLE 



V-60 



INNER BELT AND EXPRESSWAY SYST 



EXHIBIT B-26 



SEE EXHIBIT NO.B-24 
\ 





INTERCHANGE PLAN 

CAMBRIDGE-SOMERVILLE 



200 400 



SCALE IN FEET 



NORTHWEST EXPRESSWAY AND INNER BELT 

RECOMMENDED LOCATION 



INNER BELT AND EXPRESSWAY SYSTEM 



V-61 



J ^ 



EXHIBIT B-27 



ER ^v^ 




1975 TRAFFIC ASSIGNMENT 



* 5 



ifiS 




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2 
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£ 
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00 


CONSTRUCTION 
TERMINAL CONTROL^ 






































\ 






0.5 % SC UT> 


SOUNO^ 


COW 

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POINT N0.6 

40 
































4-1. 


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40 


20 ^^^^**"^ 




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MYSTIC VALLEY PARKWAY TO BROADWAY 
MEDFORD-SOMERVILLE 



HORIZONTAL SCALE 400 



VERTICAL SCALE 40 



40 

SCALE IN FEET 



NORTHERN EXPRESSWAY 

RECOMMENDED LOCATION 



INNER BELT AND EXPRESSWAY SYSTEM 



( ^UHLlf 



V-63 



EXHIBIT B-28 



u a. 





a. 




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INNER BELT 
SOUTHBOUND 


sou™ 


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--- v r^ "I"!"-""- - - -"- d 








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20 






VIADUCT (2 LEVEL) 

20 








' — B. a H. R.R. YARDS 

EXISTING GROUND 


BASE BASE 



CONNECTOR A 




CONNECTOR C 

NORTHERN EXPRESSWAY AND INNER BELT 

RECOMMENDED LOCATION 



HORIZONTAL SCALE 200 



VE RTICAL 5CALE 20 




CONNECTOR B 






■"- — — — _ 




^^^^ M% 
















s„„^ 








0.5 % 





-_. 


— Jij-yt,. 


1.0 °/ 




^ ' 4 % 










10 







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so 


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LEV 


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1 










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3ASE 








BASE 



CONNECTOR D 



200 



O 20 

SCALE IN FEET 



INTERCHANGE PROFILES 
SOMERVILLE-BOSTON 



V-64 



I N N 



ER BELT AND EXPRESSWAY SYS 



EXHIBIT B-29 



INTERCHANGE PLAN 
SOMERVILLE-BOSTON 



SEE EXHIBIT NO. B-27 






SCALE IN FEET 



SEE EXHIBIT NO.B-II 

NORTHERN EXPRESSWAY AND INNER BELT 

RECOMMENDED LOCATION 



INNER BELT AND EXPRESSWAY SYSTEM 



V-65 



EXHIBIT B-30 



6-6" SUBSURFACE 

drain^ „Lo»n T '-6"RELOeATED-. SOUTHW_EST_ EXPRESSWAY 
elected \ SUB8UP,FACC DBA,N 




1975 TRAFFIC ASSIGNMENT 



CONSTRUCTION 
COMPLETED 

TERMINAL CONTROL 
POINT NO. I 




INNER BELT 

RECOMMENDED LOCATION-ALTERNATE DESIGN I 



HORIZONTAL SCALE 400 
VERTICAL SCALE 40 



600 



40 

SCALE IN FEET 



V-66 



MASSACHUSETTS AVENUE TO BROOKLINE AVENUE 

BOSTON 

INNER BELT AND EXPRESSWAY SYST* 



EXHIBIT B-31 




PARK DRIVE 



1975 TRAFFIC ASSIGNMENT 




BROOKLINE AVENUE TO WATSON STREET 

BOSTON-BROOKUNE-CAMBRIDGE 



IORIZONTAl SCALE 400 



VERTICAL SCALE 40 



40 

SCALE IN FEET 



INNER BELT 

RECOMMENDED LOCATION-ALTERNATE DESIGN I 



J 



NNER BELT AND EXPRESSWAY SYSTEM 



V-67 



EXHIBIT B-32 
I 




6-S BOSTON MAIN 
.DRAINAGE RELIEF 




CONNECTOR A 



CONNECTOR B 



t- 
z 

s 

m 

J 


M 

1- 
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1 

a 

u 


o 

X 
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w 

> 




■ 
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3 


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z 




Id 

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9 
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z 

4 
CC 




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a 

-i 
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3 

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X 

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p 


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s. 


















40 










CONN. B 












40 




V 1 A 


> u 


C T 


















10 














*^»/._ 








20 
















Kg 


ho 




EXISTING OROUND 












"va^j^ 


o 




RELOCATED 

H'-0"»7'-6" 


ftr 


J 






^^^^ INNER BELT 






DRAIN 


""*- ll'-0"*T L 0" 

SUBSURFACE DRAIN 






SOUTHBOUNU 
5% 








BASE -20 












BASE -20 




INNER BELT 
NORTHBOUND 

0.5' 



CONNECTOR C 



CONNECTOR D 



SOUTHWEST EXPRESSWAY AND INNER 

RECOMMENDED LOCATION-ALTERNATE DESIGN I 



HORIZONTAL SCALE ZOO 

ix2 

VERTICAL SCALE 20 



V-68 



200 

-a— 



20 

SCALE IN FEET 



INTERCHANGE PROFILES 
BOSTON 



NN 



ER BELT AND EXPRESSWAY SYS 



EXHIBIT B-33 




INTERCHANGE PLAN 
BOSTON 



SCALE IN FEET 



SOUTHWEST EXPRESSWAY AND INNER BELT 

RECOMMENDED LOCATION-ALTERNATE DESIGN I 



INNER BELT AND EXPRESSWAY SYSTEM 



V-69 



EXHIBIT B-34 







a z 
£3 



-1 
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o 

•0 




to 
a 

< 
X 


8 a «" 


u 

B 

9 


R0 

RELOC. 


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INTERCHANGE PROFILES 
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INTERCHANGE PLAN 

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INNER BELT AND MASSACHUSETTS TURNPIKE 

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V-71 



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SOUTHWEST EXPRESSWAY 
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MASSACHUSETTS AVENUE TO BROOKLINE AVENUE 

BOSTON 



SCALE IN FEET 



V-72 



NNER BELT AND EXPRESSWAY SYS 



EXHIBIT B-37 





BROOKLINE AVENUE TO HAMILTON STREET 
BOSTON-BROOKLINE-CAMBRIDGE 



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VERTICAL SCALE 40 



*0 

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BOO 
80 



INNER BELT 

RECOMMENDED LOCATION-ALTERNATE DESIGN II 



inner belt and expressway system 



V-73 



EXHIBIT B-38 




C N N E CTOR B 



il.NKe* BEIT 
SOUTHBOUND 




INNER BELT AND MASSACHUSETTS TURNPIKE 

RECOMMENDED LOCATION-ALTERNATE DESIGN II 



CONNECTOR C a CONNECTOR D 

HORIZONTAL SCALE 200 
VERTICAL SCALE 20 



INTERCHANGE PROFILES 
BROOKLINE-BOSTON-CAMBRIDGE 



V-74 



INNER BELT AND EXPRESSWAY SY 



EXHIBIT B-39 




z** 3 ^ SEE EXHIBIT NO. B-37 



INTERCHANGE PLAN 
BROOKLINE-BOSTON-CAMBRIDGE 



ZOO 400 



SCALE IN FEET 



INNER BELT AND MASSACHUSETTS TURNPIKE 

RECOMMENDED LOCATION-ALTERNATE DESIGN II 



INNER BELT AND EXPRESSWAY SYSTEM 



V-75 




LEGEND 

EXISTING EXPRESSWAYS 
OTHER PROPOSED EXPRESSWAYS 
ALTERNATE LOCATION OF 
EXPRESSWAYS STUDIED 



FALL RIVER 
@ EXPRESSWAY 



INNER BELT AND EXPRESSWAY SYSTEM 



PUBLIC 




EXHIBIT B-40 

KEY MAP 

ALTERNATE LOCATION 



V-77 



EXHIBIT B-41 



SOUTHWEST EXPRESSWAY SEE EXHIBIT NO. B-4B 



POSSIBLE M.T.A 

STRUCTURE 

RELOCATION 



M.T.A ELEVATEO TRACKS 




5-10 x 4-6 
STORM SEWER 



5IBLE 

TUNNEL 



15-6 KI7-0 
STONY BROOK 
COWOUIT 



INNER BELT 

ALTERNATE LOCATION 



HORIZONTAL SCALE 400 



400 



BOO 



VERTICAL SCALE 40 



MASSACHUSETTS AVENUE TO ST. 

BOSTON 



ALPHONSUS STREET 



SCALE IN FEET 



V-78 



INNER BELT AND EXPRESSWAY S 



y ste 



EXHIBIT B-42 




ST. ALPHONSUS STREET TO MEMORIAL DRIVE 
BOSTON-BROOKLINE-CAMBRIDGE 



VERTICAL SCALE 40 



40 

SCALE IN FEET 



INNER BELT 

ALTERNATE LOCATION 



NNER BELT AND EXPRESSWAY SYSTEM 



V-79 



EXHIBIT B-43 




V-80 



MEMORIAL DRIVE TO McGRATH HIGHWAY 

CAMBRIDGE-SOMERVILLE 

INNER BELT AND EXPRESSWAY SYS 




EXHIBIT B-44 



EXISTING GROUND 




McGRATH HIGHWAY TO PRISON POINT BRIDGE 
SOMERVILLE-BOSTON 



I0RIZ0NTAL SCALE 400 



soo 



VERTICAL SCALE 40 



SCALE IN FEET 



INNER BELT 

ALTERNATE LOCATION 



V-81 



EXHIBIT B-45 




UNDER DESIGN 
BY OTHERS 

TERMINAL CONTROL 
POINT NO. 3. 



TT'S 



CS 




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l*lE 



SOUTHWEST EXPRESSWAY 

ALTERNATE LOCATION 



HORIZONTAL SCALE 400 



400 



600 

■I 



VERTICAL SCALE 40 



ROUTE 128 TO NEPONSET VALLEY PARKWAY 
CANTON-MILTON-BOSTON 



SCALE IN FEET 



V-82 



INNER BELT AND EXPRESSWAY SYS^fl 



EXHIBIT B-46 




1975 TRAFFIC ASSIGNMENT 



1690 

2O0 ^-^M 




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3310 
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WEST 




^^ 3310 
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NEPONSET VALLEY PARKWAY TO THATCHER STREET 

BOSTON 



I0RIZ0NTAL SCALE 400 



VERTICAL SCALE 40 



40 

SCALE IN FEET 



SOUTHWEST EXPRESSWAY 

ALTERNATE LOCATION 



NNER BELT AND EXPRESSWAY SYSTEM 



V-83 



EXHIBIT B-47 




Sfis 



*•»..; 



SOUTHWEST EXPRESSWAY 

ALTERNATE LOCATION 



HORIZONTAL SCALE 400 



VERTICAL SCALE 40 



"""•iinittiiiiiiiiiiiriiii 

THATCHER STREET TO THE ARBORWAY 
BOSTON 



SCALE IN FEET 



V-84 



NNER BELT AND EXPRESSWAY S 




EXHIBIT B-48 




1975 TRAFFIC ASSIGNMENT 




6UE 0. 



POSSIBLE PROFILE MT.A TUNNEL 



minimi mi i nil HUM UHMMIII Milt III iililiif IHIIIIHI iiiitmii 






t«»»" 



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THE ARBORWAY TO HULBERT STREET 
BOSTON 

NNER BELT AND EXPRESSWAY SYSTEM 



HORIZONTAL SCALE 400 
VERTICAL SCALE 40 



SOUTHWEST EXPRESSWAY 

ALTERNATE LOCATION 



SCALE IN FEET 



V-85 



EXHIBIT B-49 




m in 

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V-86 



HORIZONTAL SCALE 200 



VERTICAL SCALE 20 



20 

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INTERCHANGE PROFILES 
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EXHIBIT B-50 




INNER BELT AND EXPRESSWAY SYSTEM 



V-87 



EXHIBIT B-51 




CON N E C TO R A 



CONNECTOR A 




CON N E CT OR 


C 


CONNECTOR 


D 



INNER BELT AND MASSACHUSETTS TURNPIKE 

ALTERNATE LOCATION 

V-88 



HORIZONTAL SCALE 200 



VERTICAL SCALE 20 



20 

SCALE IN FEET 



NNER BELT AND EXPRESSWAY SY 



EXHIBIT B-52 




INTERCHANGE PLAN 
BOSTON-BROOKLINE-CAMBRIDGE 



SEE EXHIBIT NO. B-43 



SCALE IN FEET 



INNER BELT AND MASSACHUSETTS TURNPIKE 

ALTERNATE LOCATION 



NNER BELT AND EXPRESSWAY SYSTEM 



V-89 



EXHIBIT B-53 




19 75 TRAFFIC ASSIGNMENT 



GRADING AND 
DRAINAGE COMPLETED 

TERMINAL CONTROL 
POINT NO.5 




BASE 160 



BASEIttO 



ROUTE 3 EXPRESSWAY 

ALTERNATE LOCATION 



HORIZONTAL SCALE 400 



400 



VERTICAL SCALE 40 



40 

SCALE IN FEET 



eoo 

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V-90 



ROUTE 128 TO WOBURN STREET 
BURLINGTON-WOBURN-LEXINGTON 

INNER BELT AND EXPRESSWAY SYSTEM 



EXHIBIT B-54 




WOBURN STREET TO MYSTIC STREET 
LEXINGTON-WINCHESTER-ARLINGTON 



HORIZONTAL SCALE 400 



VERTICAL SCALE 40 



SCALE IN FEET 



ROUTE 3 EXPRESSWAY 

ALTERNATE LOCATION 



NER BELT AND EXPRESSWAY SYSTEM 



V-91 



EXHIBIT B-55 




180 \ 






180 


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120 




^^ 


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100 






^x 


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B*>SE eo 



LOWER MYSTIC LAKE 



LOWER MYSTIC LAKE 



ROUTE 3 EXPRESSWAY 

ALTERNATE LOCATION 



HORIZONTAL SCALE 400 



VERTICAL SCALE 40 



40 

SCALE IN FEET 



MYSTIC STREET TO ALEWIFE BROOK PARKWAY 
ARLINGTON-MEDFORD-SOMERVILLE 



V-92 



INNER BELT AND EXPRESSWAY SYSTE|| 



EXHIBIT B-56 




584gQ 
S3 60 



NORTHWEST-NORTHERN CONNECTOR 
FREMONT STREET TO MAIN STREET 

ARLINGTON-SOMERVILLE-MEDFORD 



HORIZONTAL SCALE 400 



800 



VERTICAL SCALE 40 



ROUTE 3 EXPRESSWAY 

ALTERNATE LOCATION 



SCALE IN FEET 



NNER BELT AND EXPRESSWAY SYSTEM 



V-93 



EXHIBIT B-57 



SEE EXHIBIT NO. B-58 




ROUTE 3 EXPRESSWAY - NORTHWEST EXPRESSWAY 

ALTERNATE LOCATION 



HORIZONTAL SCALE 400 



VERTICAL SCALE 40 



SCALE IN FEET 



V-94 



NORTHWEST-NORTHERN CONNECTOR 
FREMONT STREET TO SHERMAN STREET 
ARLINGTON-SOMERVILL E-CAMBRIPGE 

INNER BELT AND EXPRESSWAY SYSTB 



EXHIBIT B-58 




4800 \y 



?2240 fi\ 
4800 N_^ 




1975 TRAFFIC ASSIGN MENT 




SHERMAN STREET TO WEBSTER AVENUE 

CAMBRIDGE-SOMERVILLE 



HORIZONTAL SCALE 400 



VERTICAL SCALE 40 



NORTHWEST EXPRESSWAY 

ALTERNATE LOCATION 



SCALE IN FEET 



INNER BELT AN 



D EXPRESSWAY SYSTEM 



V-95 



EXHIBIT B-59 



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INNER BELT AND EXPRESSWAY S 



yste 



EXHIBIT B-60 



WASHINGTON ELMS 




INTERCHANGE PLAN 
CAMBRIDGE-SOMERVILLE 



SCALE IN FEET 



NORTHWEST EXPRESSWAY AND INNER 

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BELT 



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V-97 



EXHIBIT B-61 



POINT NaV TF 




BRANCH 
LIBRARY 



LIMIT OF COST ESTIMATE 



NORTHERN EXPRESSWAY 



LIMIT OF COST ESTIMATE 



INNER BELT 



MIDDLESEX AVE 




1975 TRAFFIC ASSIGNMENT 



UNDER CONSTRUCTION 



TERMINAL CONTROL 
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«L 



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HORIZONTAL SCALE 400 



VERTICAL SCALE 40 



40 

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NORTHERN EXPRESSWAY 

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NNER BELT AND EXPRESSWAY SYSTEM 



V-99 



EXHIBIT B-62 



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VERTICAL SCALE 20 



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ALTERNATE LOCATION 



SCALE IN FEET 



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APPENDIX 



PART II 
REFERENCES 

1. Road User Benefit Analysis for Highway Improvements, American Association of Slate 

Highway Officials, Washington, D.C. (1960) p. 10. 

2. Bone, A. J., and Memmott, F. W., Travel Time Studies in Boston — I960, M.I.T. — Massa- 

chusetts Department of Public Works Joint Highway Research Report No. 35, Boston, 
Mass. (I960). 

3. Hoch, I., "Benefit-Cost Methods for Evaluating Expressway Construction," Traffic Quarterly, 

Eno Foundation for Highway Traffic Control, Sougatuck, Conn. (Apr. 1961). 

PART III 
REFERENCES 

1. "Algorithm for Finding Shortest Paths Between Pairs of Points in a Network," Armour Re- 

search Foundation Phase Report No. I to the Chicago Area Transportation Study 
(June, 1957). 

2. Anderson, T. R., "Intermetropoliton Migration," American Sociological Review, Vol. 20 

(June 1955) pp. 287-91. 

3. ._ , "Potential Models and Spatial Distribution of Population," Papers and Proceed- 

ings of the Regional Science Association, Vol. 2 (1956). 

4. Bevis, W., "A Model for Predicting Urban Travel Patterns," Journal of the American Institute 

of Planners, Special Issue, Vol. XXV, No. 2 (May 1959) pp. 87-89. 

5. Blumenfeld, H., "Are Land Use Patterns Predictable?", Journal of the American Institute of 

Planners, Vol. XXV, No. 2 (May 1959). 

6 , "On the Concentric-Circle Theory of Urban Growth," Land Economics (May 1949). 

7 _. , "Correlation Between Value of Dwelling Units and Altitude," Land Economics 

(Nov. 1948). 

8 , "The Dominance of the Metropolis" (comment), Land Economics (May, 1950). 

9 ,"The Tidal Wave of Metropolitan Expansion," Journal of the American Institute of 

Planners, Vol. XX, No. 1. 

10. Bogue, J., The Structure of the Metropolitan Community, A Study of Dominance and Sub- 

dominance, University of Michigan, Ann Arbor (1949). 

11. Bone, A. J., "Travel Time and Gasoline Consumption Studies in Boston," Proceedings of 

the 32nd Annual Meeting of the Highway Research Board, Washington, D.C. (Dec. 
1951). 

12. Bone, A. J., and Memmott, F. W., "Travel Time Studies in Boston — 1960," M.I.T. — 

Massachusetts Department of Public Works Joint Highway Research Report No. 35, 
Boston, Mass. (I960). 

13. Bright, M. L, and Thomas, D. S., "Interstate Migration and Intervening Opportunities," 

American Sociological Review, Vol. 6 (Dec. 1941) pp. 773-83. 

14. Brokke, G. E., and Mertz, W. L., "Evaluating Trip Forecasting Methods with an Electronic 

Computer," Public Roads, Vol. 30, No. 4 (Oct. 1958); also in: Highway Research Board 
Bulletin 203 (1959). 

15. Brokke, G. E., "Assigning Traffic to a Highway Network," Public Roads, Vol. 30, No. 10, 

Washington, D.C. (Oct. 1959), p. 228. 

16. , "Program for Assigning Traffic to a Highway Network," Trip Characteristics and 

Traffic Assignment, Highway Research Board Bulletin 224, Washington, D.C. (1959) 
pp. 89-90. 

17. Calland, W. B., "Traffic Forecasting & Origin-Destination Trip Assignment Techniques," 

Proceedings of the Institute of Traffic Engineers, Western Section, 1958. 

18 , "Forecasting Traffic for Freeway Planning," Journal of the American Institute of 

Planners, Vol. XXV, No. 2 (May 1959). 

19. Campbell, E. W., "A Mechanical Method for Assigning Traffic to Expressways," Traffic 

Assignment by Mechanical Methods, Highway Research Board Bulletin 130, Washington, 
D.C, (1956) p. 40. 

20. Carroll, J. D., Jr., "A Method of Traffic Assignment to an Urban Network," Trip Character- 

istics and Traffic Assignment, Highway Research Board Bulletin 224, Washington, D.C. 
(1959) p. 68. 

21. Carrothers, A. P., "An Historical Review of the Gravity and Potential Concepts of Human 

Interaction," Journal of the American Institute of Planners, Vol. XXII, No. 2 (Spring, 
1956) pp. 94-102. 

22. Cavanaugh, J. A., Formulation, Analysis, and Testing the Interactance Hypothesis, unpub- 

lished thesis. University of Washington Library, Seattle (1950). 

23. Chicago Area Transportation Study, Final Report, Vol. II, Chicago, Ml. (Jul. 1960) p. 107 

et seq. 

24. Christaller, W., Die Zentralen Orte in Suddeutschland, Gustav Fischer, Jena, Germany, 

(1933). 

25. Clark, C, "Population Movements into the Outer Suburbs of Large Cities — Measurements 

and Prediction," Report of Proceedings, Town and Country Planning Summer School, 

Town Planning Institute, University of Bristol, London (1953). 
26 , "Transportation, Maker and Breaker of Cities," The Town Planning Review (Jan. 

1958). 
27 , "Urban Population Densities," Journal of the Royal Statistical Society, Vol. CXIV, 

Port IV (1951) pp. 490-96. 



28. Dodd, S. G, "The Interactance Hypothesis: A Gravity Model Fitting Physical Masses and 

Human Groups," American Sociological Review, Vol. 15, No. 2 (Apr. 1950) pp. 245-56. 

29. Duncan, O. D., "Population Distribution and Community Structure," Cold Spring Harbor 

Symposium on Quantitative Biology, Vol. 22 (1957). 

30. Dunn, E. S., "The Market Potential Concept and the Analysis of Location," Papers and 

Proceedings of the Regional Science Association, Vol. 2 (1956). 

31. Fisher, F., and Fleischer, G., Study of Traffic Operations on Massachusetts Route 128, un- 

published thesis, M.I.T. Library, Cambridge, Mass. (1958). 

32. Fratar, T. J., "Vehicular Trip Distribution by Succession Approximations," Traffic Quarterly 

(Jan. 1954). 

33. Gill, J. D., and McCarthy, A. J., Travel Time Study on John F. Fitzgerald Expressway vs. 

Parallel City Streets, unpublished thesis, M.I.T. Library, Cambridge, Mass. (1956). 

34. Hoffman, W., Mayer, A., Pavley, R., and Smock, R., "Describing Travel Patterns in Large 

Cities," Detroit Area Traffic Study, Wayne State University (1959}. 

35. Hoffman, W„ and Pavley, R., "A Method for the Solution of the N-th Best Path Problem," 

Journal of the Association for Computing Machinery (1959). 

36. Isard, W., 'Distance Inputs and the Space-Economy, Part 1, The Conceptual Framework," 

The Quarterly Journal of Economics, 65 (May 1951) pp. 181-191. 
37 , "Distance Inputs and the Space-Economy, Part 2, The Location Equilibrium of the 

Firm," The Quarterly Journal of Economics, 65 (Aug. 1951) pp. 373-399. 

38 , Location and Space-Economy, The Technology Press, Cambridge (1956). 

39 .-, "Location Theory and Trade Theory: Short-Run Analysis," The Quarterly Journal 

of Economics, Vol. 68 {May 1954) pp. 305-320. 

40. Isbell, E. C, "Internal Migration in Sweden and Intervening Opportunities," Ameri- 

can Sociological Review, Vol. 9 (Dec. 1944) pp. 627-39. 

41. Killen, E. L., "Highway-Traffic Estimation by Linear Programming," Journal of the Highway 

Division, Proceedings of the American Society of Civil Engineers, Vol. 85, No. HW1, 
Part 1 (Jan. 1959) pp. 17-33. 

42. Kurz, C. R., and Powell, T. E., Study of Highway Travel Conditions in Metropolitan Boston, 

unpublished thesis, M.I.T. Library, Cambridge, Mass. (1948). 

43. Loesch, A., Die Naeumliche Ordnung der Wirtschaft, Second Edition, G. Fischer, Jena, 

Germany, (1944) pp. 70-71, 307-16. 
44 , The Economics of Location, Yale University Press, New Haven (1954) Table 21. 

45. Lynch, J. T., "Home-Interview Surveys & Related Research Activities," Trip Characteristics 

and Traffic Assignment, Highway Research Board Bulletin 224 (1959). 

46. McKenzie, R. D., The Metropolitan Community, New York (1933). 

47. Mertz, W. L., "Traffic Assignment to Street and Freeway Systems," Traffic Engineering, Vol. 

30, No. 10 (Jul. 1960) p. 27. 

48. Moore, E. F., "The Shortest Path Through a Maze," International Symposium on the Theory 

of Switching, Harvard University, Cambridge (1957). 

49. Moskowitz, K., "California Method of Assigning Diverted Traffic to Proposed Freeways," 

Traffic Assignment by Mechanical Methods, Highway Research Board Bulletin 130 (1956). 

50. Mylroie, W., "Evaluation of Intercity-Travel Desire," Highway Research Board Bulletin 119 

(1956) pp. 69-94. 

51. A Policy on Arterial Highways in Urban Areas, American Association of State Highway 

Officials, Washington, D. C. (1957) pp. 10, 95 et seq. 

52. Rovenstein, E. G., "The laws of Migration," Journal of the Royal Statistical Society, Vol. 

48 (Jun. 1885) pp. 167-227, and Vol. 52 (Jun. 1889) pp. 241-301. 

53. Reilly, W. J., "Methods for the Study of Retail Relationships," University of Texas Bulletin 

No. 2944 (Nov. 1929). 
54 , The Law of Retail Gravitation, Second Edition, Filsburg Publishers, New York (1953). 

55. Report on the Detroit Metropolitan Area Traffic Study, Part II, Detroit, Mich. (Mar. 1956) 

pp. 80, 81. 

56. Rivord, L. A., "Electronic Traffic Projection and Assignment," Report of Meetings of the 

A.A.S.H.O. Electronics Committee, Boston, 1959, Washington, D.C. (1959) p. 44. 

57. Row and Jurkat, "The Economic Forces Shaping Land Use Patterns," Journal Of The American 

Institute Of Planners, Vol. XXV, No. 2 (May 1959). 

58. Schmidt, R. E. and Campbell, M. E., Highway Traffic Estimation, Eno Foundation for High- 

way Traffic Control, Saugatuck, Conn. (1956) p. 135. 

59. Silver, J., "Trends in Travel to the Central Business District by Residents of the Washington, 

D.C, Metropolitan Area, 1948 and 1955," Trip Characteristics and Traffic Assignment, 
Highway Research Board Bulletin 224, Washington (1959) pp. 1-40. 

60. Smith, Wilbur, & Associates, Future Highways and Urban Growth, Automobile Manufacturers 

Association, New Haven, Conn. (1961) p. 174. 

61. Stewart, J. O., "An Intense Distance Variation for Certain Social Influences," Science N. S., 

93 (1941) p. 89. 
62 , "Empirical Mathematical Rules Concerning the Distribution and Equilibrium of 

Population," Geographical Review, Vol. XXXVII (Jul. 1947) pp. 461-85. 
63 ..., "Demographic Gravitation: Evidence and Application," Sociometry, Vol. XI (Feb.- 

May 1948) pp. 31-58. 

64 .., "Concerning Social Physics," Scientific American, Vol. 178 (May 1948) p. 22. 

65 , "The Development of Social Physics," American Journal of Physics, Vol. 18 (May 

1950) pp. 239-53. 
66 , "Potential of Population and its Relationship to Marketing," Theory in Marketing, 

edited by R. Cox and W. Alderson, Chicago (1950) pp. 19-40. 



67. Stouffer, S. A., "Intervening Opportunities: A Theory Relating Mobility and Distance," 

American Sociological Review, Vol. 5 (Dec. 1940) pp. 845-67. 

68. The Structure and Growth of Residential Neighborhoods in American Cities, Federal Hous- 

ing Administration, Washington, D.C. (1939) p. 114. 

69. "Travel in the Boston Region, 1959-1980," Studies of Urban Transportation, Boston College 

Seminar Research Bureau, 1960-61. 

70. Ullmon, E., "A Theory of Location for Cities," American Journal of Sociology, Vol. XLVl 

(May 1941) pp. 853-64. 

71. Vining, R., "Delimitation of Economic Areas; Statistical Conceptions in the Study of the 

Spatial Structure of an Economic System, " Journal of The American Statistical Associa- 
tion, Vol. 48 (Mar. 1953) pp. 44-64. 
72 , Economic Development and Cultural Change, Vol. Ill (Jon. 1955) pp. 196-198. 

73. Wood, G., "Traffic Assignment by IBM," Traffic Quarterly, Eno Foundation for Highway 

Traffic Control, Saugatuck, Conn. (Apr. 1961) p. 331. 

74. Voorhees, A.- M., and Morris, R., "Estimating and Forecasting Travel for Baltimore by Use 

of a Mathematical Model," Trip Characteristics and Traffic Assignment, Highway Re- 
search ffoard Bulletin 224, Washington (1959) pp. 105-114. 

75. Voorhees, A. M., "A General Theory of Traffic Movement," Proceedings, Institute of Traffic 

Engineers (1959). 

76. , "The Nature & Uses of Models in City Planning," Journal of the American Institute 

of Planners, Vol. XXV, No. 2 (May 1959). 

77 , "Use of Mathematical Models in Estimating Travel," Proc. ASCE, Vol. 05, HW4, 

Part 1 (Dec. 1959). 

78. Zipf, G. K., "The Unity of Nature, Least Action, and Natural Social Science," Sociometry, 

Vol. 5 (Feb. 1942). 

79. , "The P1P2/D Hypothesis: (he Case of Railway Express," Journal of Psychology, 

Vol. 22 (Jul. 1946) pp. 3-8. 

80 , "The P1P2/D Hypothesis: on the Intercity Movement of Persons," American Socio- 
logical Review (Dec. 1946). 

81 , Human Behavior and The Principle of Least Effort, Addison-Wesley Press, Cambridge 

(1949). 

PART IV 
REFERENCES 

1. Banker & Tradesman, Warren Publishing Corp., Boston, Mass., Vol. CXXXVII, No. 31, to 

Vol CXXXIX, No. 9, Aug. 2, 1958-Feb. 27, I960; values estimated at the rate of $1.10 
tax stamps per $1000 selling price. 

2. Bone, A. J. and Wohl, M., Economic Impact Study of Massachusetts Route 128, Massachu- 

setts Institute of Technology, Cambridge, Mass., 1958. 

3. Gery, F. W., New England Business Review, Boston Federal Reserve Bank, Boston, Mass., 

August 1959. 

4. Third Progress Report of the Highway Cost Allocation Study, House Document No. 91, 86th 

Congress, 1st Session, 1959. 
5 Johnson, R., An Analysis of the Changing Pattern of Massachusetts Manufacturing Produc- 
tion and Jobs, 1960-7970, Associated Industries of Massachusetts, Boston, Mass., 1959. 

6. Jurkat, E., Baltimore Central Business District Projections, Marketers Research Service, Inc., 

May 1959 (Mimeo). 

7. Long Range Projections for Economic Growth in the American Economy Through 1970, 

National Planning Association, Washington, D.C, 1959. 

8. Sweetser, F. L., The Population of Greater Boston Projected to 1970, Greater Boston Eco- 

nomic Study Committee, Boston, Mass., June 1959. 

SELECTED BIBLIOGRAPHY 

Balfour, F. C, "California's Land Economic Studies Along Controlled Access Highways," 

Traffic Quarterly, Vol 1:1, January 1958. 
Garrison, W. L., Berry, B. J. L., Marble, D. F., Nystuen, J. O., Morrill, R. L., Studies of Highway 

Development and Geographic Change, University of Washington Press, Seattle, Wash., 

1959, pp. 20-35. 
Isard, W. and Coughlin, R., Municipal Costs and Revenues Resulting from Community Growth, 

Chandler Davis Publishing Co., Wellesley, Massachusetts, 1957. 
Johnston, W. W., "Travel Time and Planning," Traffic Quarterly, January 1956, Vol. 10:1 pp. 

67-68. 
U. S. Dept. of Commerce, U. S. Income and Output, Washington, D. C, 1959 
U. S. Dept. of Labor, Bureau of Labor Statistics, Population and Labor Force Projections for the 

United States 7960-1975, Bulletin 1242, Washington, D.C, 1959. 
Von Bertalanffy, L., General System Theory: A New Approach to the Unity of Science, 47th 

Annual Meeting of American Philosophical Association, Eastern Division, Toronto, Canada, 

December 1950. 
Warner, A. E., The Impact of Highways on Land Use and Properly Values, Highway Traffic 

Safety Center. Michigan State University. March 1958. 
Warner, W., Residential Redevelopment of the West End of Boston, unpublished thesis, M. I. T. 

Library, Cambridge, Mass. (1958). 
Wheaton, L. C and Schussheim, M. L., The Cost of Municipal Services in Residential Areas, 

U. S. Housing and Home Finance Agency, 1953. 




N 



INNER BELT AND EXPRESSWAY SYSTEM 




V-103 



x